Question

If A, B are
complementary angles then cos² A + cos² B=_____
1.1
2. -1
3.2
4. 0​

Answer 1

Answer:

1.1

Step-by-step explanation:

Since, A+B=90°

so, A=90°-B

${ \cos }^{2} a = { \cos }^{2} (90 - b) \\ = { \sin }^{2} a$

So,

${ \sin }^{2} a + { \cos }^{2} a = 1$