Question

plz solve it it's important for me it's important problem of trigonometry

Answer 1

HEY DEAR,

HERE IS YOUR ANSWER...........

ITS AN IDENTITY DUDE..

2 COS^2 (THETA) = 1 + COS 2(THETA)

SO,

2 COS^2 (45-{THETA}) = 1 + COS 2(45-{THETA})

                                       => 1 + COS (90- {2THETA})..................(1.)

 AS WE KNOW ,      COS (90 - {THETA }) => SIN(THETA)

PUT IN 1 EQUATION...

                                       => 1 + SIN (2THETA)

HENCE ...

L.H.S = R.H.S

            SO, PROVED..............

HOPE IT HELPS YOU ..

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THANKS.....

MARK IT BRAINLIEST PLZ IFIT HELPS YOU..

Answer 2

Given Equation is 2 cos²(45 - θ).

We know that cos 2θ = 2cos²θ - 1 (or) cos 2θ + 1 = 2cos²(θ).

⇒ cos 2(45 - θ) + 1

⇒ cos(90 - 2θ) + 1

We know that cos(90 - θ) = sin θ.

⇒ sin 2θ + 1.

Hope this helps!