If sin theta 45 and theta is in QII find cos theta tan the

If sin theta = 4/5 and theta is in QII, find cos theta & tan theta. Verify the identity: 1 - sin^2 x/cos x = cos x Verify the identity: cos^2 x tan^2 x + cos^2 x = 1 Solve (sin x + l)(tan x - 1) = 0 in the interval [0, 2 pi) Solve 4cos^2x = 1 in the interval [0, 2 pi). Find the exact value of sin(60 degree + 45 degree). Find the exact value of cos(285 degree) Given sin theta = -3/5, theta in Q4. Find sin 2 theta cos 2 theta Solve right triangle ABC if a = 5 and c = 10. A 15-foot ladder is resting against a wall of a building in such a way that the top of the ladder the ground. How far is the foot of the ladder from the base of the building? (Draw the the required value.) Solve triangle ABC with A = 70 degree, B = 65 degree and a = 16 inches. Solve triangle ABC with a = 4, b = 6, c = 8. If you were to post a social media status, shout out or comment about your Fall 2016 what would it be? Why? What is/are the most important thing/s youve learned from the class, the classmates? In what way/s do you think the lessons learned from Math 121 would career?

Solution

1.    sin theta=4/5    theta is in second quadrant

       opposite=4    and   hypotenuse=5

adjacent=sqrt(25-16) =3

         cosine is negative in second quadrant

cos theta= adjacent/hypotenuse =-3/5

tan theta=sin theta/cos theta= -4/3

2. (1-sin²x)/cosx=cos x

Starting with the left side

(1-sin²x)/cos x

cos²x/cos x = cos x

3.cos²xtan²x + cos²x=1

Starting with the left side

cos²x(1+tan²x)

cos²x * sec²x

cos²x * (1/cos²x) = 1