if you could just answer one that would be great?

Question

1.All the real 3's for which abs(sinx)<=are

2. if sinx=1/4 and 0 <=x<= the cosx =

3. if x+y= 90degrees which of the following is true
A. sinx=siny
B. tanx=tany
C. sinx=cosy
D. sinx+siny=1
E. sinx+cosy=1

3 is supposed to be # in 1

Answer 1

1) ????

2) sin^2 x + cos^2 x = 1, so if sin x = 1/4 we have
.... (1/4)^2 + (cos x)^2 =1,
.... cos x = sqrt(15/16) = 1/4 sqrt(15).

3) sin x = cos y; they are complements.

Answer 2

Sorry tthe questions 1 and 2 are not clear.

3. sin x = cos y since x + y = 90 (complementary angles), thus sin 60 = cos 30 and sin 30 = cos 60