trigonomentry out of ideal help ah!crying

compute..
Cos(1degree)+cos(3degree)+cos(5degree)+...+Cos(179degree)
plz show working even an hint can,t help me.Have been do maths alday my brain is fried..Ah thanks

  1. 👍
  2. 👎
  3. 👁
  1. cute problem

    recall that cos x = - cos(180 - x)
    that is
    cos(1) = - cos(179)
    cos(3) = - cos(177)
    ..
    cos(89) = - cos(91)
    cos(91) = - cos(89)
    ...
    cos(177) = - cos(3)
    cos(179) = - cos(1)

    so :
    cos1 + cos3 + ... + cos 177 + cos 179
    = (cos1+cos179) + (cos3+cos177) + ...+ (cos89+cos91)
    = 0+0+...+0+0

    = 0

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Calculus

    Find the velocity, v(t), for an object moving along the x-axis in the acceleration, a(t), is a(t)=cos(t)-sin(t) and v(0)=3 a) v(t)=sin(t) + cos(t) +3 b) v(t)=sin(t) + cos(t) +2 c) v(t)= sin(t) - cos(t) +3 d) v(t)= sin(t) - cos(t)

  2. Math

    The graph of f(x), a trigonometric function, and the graph of g(x) = c intersect at n points over the interval 0

  3. Trig

    Find sin(s+t) and (s-t) if cos(s)= 1/5 and sin(t) = 3/5 and s and t are in quadrant 1. =Sin(s)cos(t) + Cos(s)Sin(t) =Sin(1/5)Cos(3/5) + Cos(-1/5)Sin(3/5) = 0.389418 Sin(s-t) =sin(s)cos(t) - cos(s)sin(t) =sin(-3/5)cos(1/5) -

  4. need help calculus plz plz-sir steve

    if y=3e^(2x)cos(2x-3) verify that d^2y/dx^2-4dy/dx+8y=0 plz help me i tried all i could but it become too complicated for me here set u=3e^(2x) v=cos(2x-3) du/dx=6e^(2x) i used chain rule dv/dx=-2sin(2x-3)

  1. Calculus 12th grade (double check my work please)

    1.)Find dy/dx when y= Ln (sinh 2x) my answer >> 2coth 2x. 2.)Find dy/dx when sinh 3y=cos 2x A.-2 sin 2x B.-2 sin 2x / sinh 3y C.-2/3tan (2x/3y) D.-2sin2x / 3 cosh 3yz...>> my answer. 2).Find the derivative of y=cos(x^2) with

  2. Math Help Please

    What are the ratios for sin A and cos A? The diagram is not drawn to scale. Triangle Description- AB = 29 AC = 20 BC - 21 A. sin A = 20/29, cos A = 21/29 B. sin A = 21/29, cos A = 20/21 C. sin A = 21/29, cos A = 20/29****? D. sin

  3. Studying for Pre Cal exam

    Find the fourth roots of − 1/2 + (square root)3/2 i Write the roots in trigonometric form. A - w 1=cos(35°)+isin(35°) w2 =cos(125°)+isin(125°) w3 =cos(215°)+isin(215°) w4 =cos(305°)+isin(305°) B - w1

  4. self-study calculus

    Sketch the curve with the given vector equation. Indicate with an arrow the direction in which t increases. r(t)=cos(t)I -cos(t)j+sin(t)k I don't know what to do. I let x=cos(t), y=-cos(t) and z= sin(t). Should I let t be any

  1. Pre-Cal (Trig) Help?

    The following relationship is known to be true for two angles A and B: cos(A)cos(B)-sin(A)sin(B)=0.957269 Express A in terms of the angle B. Work in degrees and report numeric values accurate to 2 decimal places. So I'm pretty

  2. math

    Can you please check my work. A particle is moving with the given data. Find the position of the particle. a(t) = cos(t) + sin(t) s(0) = 2 v(0) = 6 a(t) = cos(t) + sin(t) v(t) = sin(t) - cos(t) + C s(t) = -cos(t) - sin(t) + Cx + D

  3. Math question - plz correct

    Two airplanes leave an airport at the same time. One travels at 355km/h and the other at 450km/h. Two hrs later they are 800km apart. Find the angle between their courses. a^2 = b^2 + c^2 - 2bc Cos A 800^2= 450^2 + 355^2 -

  4. math

    if cos(B-C)+cos(C-A)+cos(A-B)=-3/2 then prove that cosA+cosB+cosC=O and sinA+sinB+sinC=O after that prove that cos(B-C)=cos(C-A)=cos(A-B)=-1/2

You can view more similar questions or ask a new question.