Question

5
If cos²A + cos²A = 1 then prove that:
sec²A - sec²A =1​

Answer 1

Step-by-step explanation:

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

$2 {cos}^{2} a = 1$

${cos}^{2} a = 1 \div 2$

Cos a = 1/ \sqrt{2}

i.e a = 45 degree