Math, asked by Skillrex420, 1 year ago

Prove that: 2Cos^2A-1/sinA cosA =cosA-tanA

MansiGarg1111: in the QUESTION is it 2cos²A?

MansiGarg1111: on L.HS

shalu223927: left hand side

MansiGarg1111: no no.. i was asking if in the question on the left hand side if is 2cos²A or 2cos2A?

Skillrex420: That's square

Skillrex420: ^ refers to the exponential form

shalu223927: 2cos²A

Skillrex420: Yes

shalu223927: it must be print mistake

Skillrex420: It's not a mistake but in my keyboard I can't type exponential forms therefore I used the symbol so it's on purpose

Answers

Answered by shalu223927

LHS = cot A - tan A. = (cos A / sin A) - (sin A / cos A). = (cos2A - sin2A) / (sin A cos A). = [ cos2A - (1 - cos2A)] / (sin A cos A) {Since sin2Θ = 1 - cos2Θ }. = (cos2A - 1 + cos2A) / (sin A cos A). = (2 cos2A - 1) / (sin A cos A).

Answered by krithikasmart11

Answer:

Proved.

Step-by-step explanation:

Given,

2 cos²A-1/sinA cosA = cosA - tanA

LHS:

cot A - tan A. = (cos A / sin A) - (sin A / cos A).

= (cos²A - sin²A) / (sin A cos A).

= [ cos²A - (1 - cos²A)] / (sin A cos A)

{Since sin²Θ = 1 - cos²Θ }.

= (cos²A - 1 + cos²A) / (sin A cos A).

= (2 cos²A - 1) / (sin A cos A).

Hence, PROVED.

#SPJ2

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