which of the following is a trigonometric identity
a. sin^2theta tan ^2 theta = tan^2 theta + sin ^2 theta
b. sec^2 theta-1/sec^2theta=cos^2 theta
c.cos^2 theta-sin^2 theta=1-2sin^2theta
d. sin^2theta=cos^2 theta-1

i believe the answer is a

Question

which of the following is a trigonometric identity
a. sin^2theta tan ^2 theta = tan^2 theta + sin ^2 theta
b. sec^2 theta-1/sec^2theta=cos^2 theta
c.cos^2 theta-sin^2 theta=1-2sin^2theta
d. sin^2theta=cos^2 theta-1

i believe the answer is a

neer2890 · Answer

yup... a option is correct...!

sidsiddhartha · Answer

its C
because 
cos2(theta)=.cos^2 theta-sin^2 theta=1-2sin^2theta

sidsiddhartha · Answer

how can u say a is correct @neer2890

neer2890 · Answer

my mistake @sidsiddhartha, question asked for identity. i solved option a and didn't checked for other options