Maths

sin(x)+cos(x)=2/3

find the value of

sin(x)

  1. 👍 0
  2. 👎 0
  3. 👁 130
  1. square both sides
    sin^2 x + 2sinxcosx + cos^2 x = 4/9
    1 + sin 2x = 4/9
    sin 2x = -5/9

    2x = 213.75 or 2x = 326.25
    x = 106.87º or x = 163.126º

    but since we performed a "squaring" operation we have to verify each answer.

    when x = 106.87 , sin106.87 + cos106.87 = .66676.., so that works

    but for x= 163.126, the result was -.66676 which is NOT the right side

    so sinx = sin106.87 = .9569

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. calculus

    Find complete length of curve r=a sin^3(theta/3). I have gone thus- (theta written as t) r^2= a^2 sin^6 t/3 and (dr/dt)^2=a^2 sin^4(t/3)cos^2(t/3) s=Int Sqrt[a^2 sin^6 t/3+a^2 sin^4(t/3)cos^2(t/3)]dt =a Int

  2. 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

  3. calculus

    Find the points on the curve y= (cos x)/(2 + sin x) at which the tangent is horizontal. I am not sure, but would I find the derivative first: y'= [(2 + sin x)(-sin x) - (cos x)(cos x)]/(2 + sin x)^2 But then I don't know what to

  4. Math

    3. find the four angles that define the fourth root of z1=1+ sqrt3*i z = 2 * (1/2 + i * sqrt(3)/2) z = 2 * (cos(pi/3 + 2pi * k) + i * sin(pi/3 + 2pi * k)) z = 2 * (cos((pi/3) * (1 + 6k)) + i * sin((pi/3) * (1 + 6k))) z^(1/4) =

  1. Calculus

    Consider the function f(x)=sin(1/x) Find a sequence of x-values that approach 0 such that (1) sin (1/x)=0 {Hint: Use the fact that sin(pi) = sin(2pi)=sin(3pi)=...=sin(npi)=0} (2) sin (1/x)=1 {Hint: Use the fact that sin(npi)/2)=1

  2. Calculus

    For the functions f(x) = sin x, show with the aid of the elementary formula sin^2 A = 1/2(1-cos 2A) that f(x+y) - f(x) = cos x sin y-2 sin x sin^2 (1/2y).​

  3. tigonometry

    expres the following as sums and differences of sines or cosines cos8t * sin2t sin(a+b) = sin(a)cos(b) + cos(a)sin(b) replacing by by -b and using that cos(-b)= cos(b) sin(-b)= -sin(b) gives: sin(a-b) = sin(a)cos(b) - cos(a)sin(b)

  4. trig

    The expression 4 sin x cos x is equivalent to which of the following? (Note: sin (x+y) = sin x cos y + cos x sin y) F. 2 sin 2x G. 2 cos 2x H. 2 sin 4x J. 8 sin 2x K. 8 cos 2x Can someone please explain how to do this problem to

  1. 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) -

  2. Calculus

    Find the velocity, v(t), for an object moving along the x-axis if 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) =

  3. calculus/Trig

    Suppose you wish to express sin(3t) in terms of sint and cost. Apply the sum formula to sin(3t) = sin(t+2t) to obtain an expression that contains sin(2t)=sin(t+t) and cos(2t)=cos(t+t). Apply the sum formulas to those two

  4. triggggg help

    Let cos 67.5° = [√(2(+√2)]/2, find tan 67.5°. Show work and simplify. I'm not too sure if i'm doing this correct. I know that the given is cos 67.5° = [√(2(+√2)]/2 sin^2 x + cos^2 x = 1 x=67.5° sin^2 67.5° + cos^2

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