Algebra II

posted by .

Find cos theta if sin theta = 3/5 and 90 degrees<theta<180 degrees.

Is the answer -sqrt34/5?

Appreciate you checking my anwers.

  • Algebra II -

    cos is - in second quadrant
    this is a 3,4,5 right triangle but anyway
    3^2 + x^2 = 25
    x^2 = 16
    x = 4 but actually -4 because in quadrant 2
    cos t = -4/5

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Pre Cal

    sin theta - 2sin^2 theta = 0 I'm using the up carrot sign to signal "to the power of..." Let sin theta = x x - 2 x^2 = 0 x (1 - 2x) = 0 Both x=0 and x = 1/2 are solutions. theta = 0 degrees, 30 degrees, 150 degrees and 180 degrees. …
  2. Trig(3 all with work)

    1)Find the exact value of cos 105 by using a half-angle formula. A)sqrt 2 - sqrt 3 /2 B)-sqrt 2 - sqrt 3 /2 C)-sqrt 2 + sqrt 3 /2 D)sqrt 2 + sqrt 3 /2 cos 105 cos 105 = cos 210/2 sqrt 1 + 210/2 sqrt 1 + sqrt 3/2 /2 sqrt 2 + sqrt 3/2 …
  3. Trig(continued)

    2)Find the solution of sin2 theta = cos theta if 0 -< theta < 180 A)30 degrees and 90 degrees B)30 degrees and 150 degrees C)30 degrees, 90 degrees, 150 degrees D)0 degrees, 90 degrees, and 150 degrees sin2 theta = cos theta …
  4. Calculus

    I wanted to confirm that I solved these problems correctly (we had to convert the polar curves to Cartesian equations). 1.rcos(theta)=1 x=1 2.r=2*sin(theta)+2*cos(theta) r^2=2rsin(theta)+2rcos(theta) x^2+y^2=2y+2x (a little unsure …
  5. Pre Calc.

    Use the sum or difference identity to find the exact value of sin255 degrees. My answer: (-sqrt(2)- sqrt(6)) / (4) Find the value of tan (alpha-beta), if cos alpha= -3/5, sin beta= 5/13, 90<alpha<180, and 90<beta<180. My …
  6. trig 30

    If cos^2 theta -6 sin 2 theta =0, one value of theta is a)0 degrees b) 90 degrees c)180 degrees or D)255 degrees. Please show me how to do it and not just give answer cause I have two more questions that are similar. Thanks so much.
  7. trigonomtry

    can you correct the rest for me please? Express each as a function of theta: a. sin (270deg + theta)= cos theta b. cos (pi + theta)= -cos theta c. tan (810 + theta)= ?
  8. trigonometry

    can you correct the rest for me please? Express each as a function of theta: a. sin (270deg + theta)= cos theta b. cos (pi + theta)= -cos theta c. tan (810 + theta)= ?
  9. trigonometry

    can you correct the rest for me please? Express each as a function of theta: a. sin (270deg + theta)= cos theta b. cos (pi + theta)= -cos theta c. tan (810 + theta)= ?
  10. Algebra II

    Multiple Choice (theta) means the symbol 0 with the dash in it. 1.)Which expression is equivalent to tan(theta)-(sec(theta))/(sin(theta))?

More Similar Questions