Math, asked by Akashkhaira, 1 year ago

if cos Theta-sin theta =√2sin theta,prove that cos theta+sin theta=√2cosTheta


jeisuggaj: let theta = x

cos x  + sin x = root2 cos x

squaring on both side, we get......

cos2x + sin2x + 2cosxsinx = 2cos2x

2sinxcosx = 2cos2x - cos2x - sin2x

2sinxcosx = cos2x - sin2x

2sinxcosx = (cosx+sinx) (cosx - sinx)

2sinxcosx = (root2 cosx) (cosx - sinx)

2sinxcosx/root2 cosx = cosx - sinx

root2 sinx = cosx - sinx
jeisuggaj:
means space hope my answer helps
Akashkhaira: htt
jeisuggaj: ??
Akashkhaira: joking yaar
Akashkhaira: nice answer , thanks
jeisuggaj: any time dude
Akashkhaira: hmm

Answers

Answered by SakshaM725
8
Let theta be A

CosA - SinA = √2SinA

CosA = √2SinA + SinA

CosA = SinA (√2 + 1)

CosA / (√2 + 1) = SinA

On rationalizing we get

CosA(√2 - 1) / 2 - 1 = SinA

√2CosA - CosA = SinA

√2CosA = SinA + CosA

Hence Proved.
Answered by Mayank750
1
sA+sinA=√​2​​​cosA​=>cos​2​​A+sin​2​​A+2cosAsinA=2cos​2​​A​=>−cos​2​​A+2cosAsinA−sin​2​​a=−2sin​2​​A​=>−(cosA−sinA)​2​​=−2sin​2​​A​=>cosA−sinA=√​2​​​sinA
Similar questions