Math, asked by ak6582148, 9 months ago

sinA/1+cosA + sinA/1-cosA= 2cosecA​

Answers

Answered by dassp71723
8

MARK IT AS THE BRAINLIEST

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Answered by Tomboyish44
3

\sf Question: To \ Prove \ \dfrac{sinA}{1 + cosA} + \dfrac{sinA}{1 - cosA} = 2 \ cosecA

Proof:

\sf LHS = \dfrac{sinA}{1 + cosA} + \dfrac{sinA}{1 - cosA}

Taking sinA as common outside we get,

\sf LHS = sinA \times \left(\dfrac{1}{1 + cosA} + \dfrac{1}{1 - cosA}\right)

\sf LHS = sinA \times \left( \ \dfrac{1 - cosA + 1 + cosA}{(1 + cosA)(1 - cosA)} \ \right)

Using (a - b)(a + b) = a² - b²

\sf LHS = sinA \times \left(\dfrac{2}{(1^2 - cos^2A)}\right)

Using 1 - cos²A = sin²A we get,

\sf LHS = sinA \times \left(\dfrac{2}{sin^2A}\right)

Cancelling sinA we get,

\sf LHS = \left(\dfrac{2}{sinA}\right)

\sf LHS = 2 \times \left(\dfrac{1}{sinA}\right)

But 1/sinA = cosecA, therefore,

\sf LHS = 2 \times cosecA

\sf LHS = 2 \ cosecA

LHS = RHS.

Hence Proved.

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