Question

4
which of the following is an identity ?
a) sin²u=1+cos²u
b) cot u = sin u*cos u
c) sin²u=1-1/sec²u
d) cos(-u)=-cos u​

Answer 1

Answer:

I think c is right answer

Answer 2

Answer:

4

which of the following is an identity ?

a) sin²u=1+cos²u

b) cot u = sin u*cos u

c) sin²u=1-1/sec²u

d) cos(-u)=-cos u

Step-by-step explanation:

c) sin²u=1-1/sec²u