2If cos Afind the value of 4 + 4 tan A.

1.	2If cos Afind the value of 4 + 4 tan A.
Answer» Given that :cos A = 2/5 we have to find :4 +4tan²A = ? solution :-we know that :(1 + tan² x ) = sec²xandsecx = 1 / cos x Here,4 + 4 tan² A = 4 (1 + tan² A) = 4 * sec²A = 4 / cos²A = 4 * (5/2)² = 4 * 25 / 4 = 25 Given that :cos A = 2/5 we have to find :4 +4tan²A = ? solution :-we know that :(1 + tan² x ) = sec²xandsecx = 1 / cos x Here,4 + 4 tan² A = 4 (1 + tan² A) = 4 * sec²A = 4 / cos²A = 4 * (5/2)² = 4 * 25 / 4 = 25

Answer»

Given that :cos A = 2/5

we have to find :4 +4tan²A = ?

solution :-we know that :(1 + tan² x ) = sec²xandsecx = 1 / cos x

Here,4 + 4 tan² A = 4 (1 + tan² A)

= 4 * sec²A

= 4 / cos²A

= 4 * (5/2)²

= 4 * 25 / 4

= 25