Maths-
General
Easy

Question

The normal y = mx – 2am – am2 to the parabola y2 = 4ax subtends a right angle at the origin, then-

  1. m = 1    
  2. m = square root of 2    
  3. m = 2    
  4. m = fraction numerator 1 over denominator square root of 2 end fraction    

The correct answer is: m = square root of 2



    Standard equation of the normal at P(at2, 2at) is y + xt = 2at + at3.
    Hence t = – m. This meets the parabola again at Q whose parameter is – t – fraction numerator 2 over denominator t end fraction or m +fraction numerator 2 over denominator m end fraction
    therefore coordinates of Q are a open parentheses m plus fraction numerator 2 over denominator m end fraction close parentheses to the power of 2 end exponent, 2a open parentheses m plus fraction numerator 2 over denominator m end fraction close parentheses
    Since angle P O Q equals 90 to the power of ring operator end exponent rightwards double arrow open parentheses fraction numerator 2 over denominator m plus fraction numerator 2 over denominator m end fraction end fraction close parentheses open parentheses fraction numerator 2 over denominator negative m end fraction close parentheses equals negative 1
    table row cell rightwards double arrow m to the power of 2 end exponent plus 2 equals 4 end cell row cell rightwards double arrow m equals plus-or-minus square root of 2 end cell end table
    m = square root of 2 is one of the choices.

    Related Questions to study

    General
    maths-

    If the point (2a, a) lies inside the parabola x2 – 2x – 4y + 3 = 0, then a lies in the interval-

    If the point (2a, a) lies inside the parabola x2 – 2x – 4y + 3 = 0, then a lies in the interval-

    maths-General
    General
    maths-

    The parametric equation of a parabola is x = 4t2, y = 8t. The tangents at the points whose parameters are fraction numerator 1 over denominator 2 end fraction and 1 meet on the line -

    The parametric equation of a parabola is x = 4t2, y = 8t. The tangents at the points whose parameters are fraction numerator 1 over denominator 2 end fraction and 1 meet on the line -

    maths-General
    General
    maths-

    Let F be the focus of the parabola y2 = 4ax and M be the foot of perpendicular from point P(at2, 2at) on the tangent at the vertex. If N is a point on the tangent at P then fraction numerator M N over denominator F N end fraction equals-

    Let F be the focus of the parabola y2 = 4ax and M be the foot of perpendicular from point P(at2, 2at) on the tangent at the vertex. If N is a point on the tangent at P then fraction numerator M N over denominator F N end fraction equals-

    maths-General
    parallel
    General
    physics-

    The equation y equals 0.15 sin invisible function application 5 x cos invisible function application 300 t comma describes a stationary wave. The wavelength of the stationary wave is

    The equation y equals 0.15 sin invisible function application 5 x cos invisible function application 300 t comma describes a stationary wave. The wavelength of the stationary wave is

    physics-General
    General
    Maths-

    If the derivative of f(x) w.r.t x is fraction numerator fraction numerator 1 over denominator 2 end fraction – sin to the power of 2 end exponent invisible function application x over denominator f left parenthesis x right parenthesis end fraction then period of f(x) is-

    If the derivative of f(x) w.r.t x is fraction numerator fraction numerator 1 over denominator 2 end fraction – sin to the power of 2 end exponent invisible function application x over denominator f left parenthesis x right parenthesis end fraction then period of f(x) is-

    Maths-General
    General
    maths-

    If not stretchy integral fraction numerator cos invisible function application x over denominator sin invisible function application left parenthesis x – alpha right parenthesis end fraction = A log sin (x – α) – B x + C then (A, B) =

    If not stretchy integral fraction numerator cos invisible function application x over denominator sin invisible function application left parenthesis x – alpha right parenthesis end fraction = A log sin (x – α) – B x + C then (A, B) =

    maths-General
    parallel
    General
    maths-

    ∫ [1 + tan x α tan (x + α)] dx is equal to -

    ∫ [1 + tan x α tan (x + α)] dx is equal to -

    maths-General
    General
    physics-

    A sound wave of wavelength 32 cm enters the tube at S as shown in the figure. Then the smallest radius r so that a minimum of sound is heard at detector D is

    A sound wave of wavelength 32 cm enters the tube at S as shown in the figure. Then the smallest radius r so that a minimum of sound is heard at detector D is

    physics-General
    General
    physics-

    The rope shown at an instant is carrying a wave travelling towards right, created by a source vibrating at a frequency n. Consider the following statements

    I.The speed of the wave is 4 n cross times a b
    II.The medium at a will be in the same phase as d after fraction numerator 4 over denominator 3 n end fraction s
    III.The phase difference between b and e is fraction numerator 3 pi over denominator 2 end fraction
    Which of these statements are correct

    The rope shown at an instant is carrying a wave travelling towards right, created by a source vibrating at a frequency n. Consider the following statements

    I.The speed of the wave is 4 n cross times a b
    II.The medium at a will be in the same phase as d after fraction numerator 4 over denominator 3 n end fraction s
    III.The phase difference between b and e is fraction numerator 3 pi over denominator 2 end fraction
    Which of these statements are correct

    physics-General
    parallel
    General
    physics-

    Intensity level 200 cm from a source of sound is 80 blank d B. If there is no loss of acoustic power in air and intensity of threshold hearing is 10 to the power of negative 12 end exponent W m to the power of negative 2 end exponent then, what is the intensity level at a distance of 4000 cm from source

    Intensity level 200 cm from a source of sound is 80 blank d B. If there is no loss of acoustic power in air and intensity of threshold hearing is 10 to the power of negative 12 end exponent W m to the power of negative 2 end exponent then, what is the intensity level at a distance of 4000 cm from source

    physics-General
    General
    physics-

    In a sonometer wire, the tension is maintained by suspending a 50.7 kg mass from the free end of the wire. The suspended mass has a volume of 0.0075 blank m to the power of 3 end exponent. The fundamental frequency of the wire is 260 Hz If the suspended mass is completely submerged in water, the fundamental frequency will become (take g equals 10 blank m s to the power of negative 2 end exponent)

    In a sonometer wire, the tension is maintained by suspending a 50.7 kg mass from the free end of the wire. The suspended mass has a volume of 0.0075 blank m to the power of 3 end exponent. The fundamental frequency of the wire is 260 Hz If the suspended mass is completely submerged in water, the fundamental frequency will become (take g equals 10 blank m s to the power of negative 2 end exponent)

    physics-General
    General
    Maths-

    If ellr means (log log log......), the log being repeated r times, then
    not stretchy integral left curly bracket x l left parenthesis x right parenthesis l to the power of 2 end exponent left parenthesis x right parenthesis l to the power of 3 end exponent left parenthesis x right parenthesis.... l to the power of r end exponent left parenthesis x right parenthesis right curly bracket to the power of negative 1 end exponent d xis equal to

    If ellr means (log log log......), the log being repeated r times, then
    not stretchy integral left curly bracket x l left parenthesis x right parenthesis l to the power of 2 end exponent left parenthesis x right parenthesis l to the power of 3 end exponent left parenthesis x right parenthesis.... l to the power of r end exponent left parenthesis x right parenthesis right curly bracket to the power of negative 1 end exponent d xis equal to

    Maths-General
    parallel
    General
    physics-

    A man standing between two parallel hills, claps his hand and hears successive echoes at regular intervals of 11s If velocity of sound is 340 m s to the power of negative 1 end exponent comma then the distance between the hills is

    A man standing between two parallel hills, claps his hand and hears successive echoes at regular intervals of 11s If velocity of sound is 340 m s to the power of negative 1 end exponent comma then the distance between the hills is

    physics-General
    General
    physics-

    A massless rod is suspended by two identical strings AB and CD of equal length. A block of mass m is suspended from point O such that B Ois equal to ´ ´ x ´ ´ Further, it is observed that the frequency of 1st harmonic (fundamental frequency) in AB is equal to 2nd harmonic frequency in CD. Then, length of BO is

    A massless rod is suspended by two identical strings AB and CD of equal length. A block of mass m is suspended from point O such that B Ois equal to ´ ´ x ´ ´ Further, it is observed that the frequency of 1st harmonic (fundamental frequency) in AB is equal to 2nd harmonic frequency in CD. Then, length of BO is

    physics-General
    General
    physics-

    If the velocity of sound in air is 336 m/s The maximum length of a closed pipe that would produce a just audible sound will be

    If the velocity of sound in air is 336 m/s The maximum length of a closed pipe that would produce a just audible sound will be

    physics-General
    parallel

    card img

    With Turito Academy.

    card img

    With Turito Foundation.

    card img

    Get an Expert Advice From Turito.

    Turito Academy

    card img

    With Turito Academy.

    Test Prep

    card img

    With Turito Foundation.