Advertisement Remove all ads

If Sin θ + Sin2 θ = 1, Then Cos2 θ + Cos4 θ = - Mathematics

MCQ

If sin θ + sin2 θ = 1, then cos2 θ + cos4 θ = 

Options

  • −1

  • 1

  • None of these

Advertisement Remove all ads

Solution

Given: 

`sin θ+sin^2θ=1` 

`⇒ 1-sin^2θ= sin θ`

Now,

`cos^2θ+cos^4θ`  

`= cos^2 θ+cos^2θcos^2θ`

=` cos^2θ+(1-sin^2θ)(1-sin^2θ)`

`=cos^2θ+sinθ sinθ`

`=cos^2 θ+sin^2θ`

`=1`

  Is there an error in this question or solution?
Advertisement Remove all ads

APPEARS IN

RD Sharma Class 10 Maths
Chapter 11 Trigonometric Identities
Q 20 | Page 58
Advertisement Remove all ads
Advertisement Remove all ads
Share
Notifications

View all notifications


      Forgot password?
View in app×