Question

If COSA+secA=5/2 then Cos^2
A+sec^2 A
O
21/4
O 17/4
O 29/4
O 33/4​

Answer 1

Answer:

17/4

hope your test goes well

Answer 2

The correct answer is 17/4 (2nd option)

Given,

cosA + secA = 5/2

To Find,

cos²A + sec²A

Solution,

This can be solved using a very simple method

We have been given that cosA + secA = 5/2

Square LHS and RHS of the given equation. We get:

⇒ (cosA + secA)² = (5/2)²

⇒ cos²A + sec²A + 2 cosA secA = 25/4

secA = 1/cosA

⇒ cosA secA = 1

Therefore, the above equation becomes

⇒ cos²A + sec²A + 2 = 25/4

⇒ cos²A + sec²A = 25/4 - 2

⇒ cos²A + sec²A = (25-8)/4

⇒ cos²A + sec²A = 17/4

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