If sinx = cos2x, then cos2x(1 + cos2x) is equal to
(A) 0 (B) 1
(C) 2 (D) none of these
If sinx = cos2x, then cos2x(1 + cos2x) is equal to
(A) 0 (B) 1
(C) 2 (D) none of these
(A) 0 (B) 1
(C) 2 (D) none of these
Anoushka Arora , 9 Years ago
Grade 10
Trigonometry> If sinx = cos2x, then cos2x(1 + cos2x) is...
2 Answers
Karthikk Kumaresan
Anoushka Arora,
Answer is (B) 1
Explanation
Squaring on both sides, we get
sin2x= cos4x
1-cos2x=cos4x
So cos2x+cos4x = 1
cos2x(1+cos2x) = 1
Hence Proved.
Warm Regards,
Karthikk Kumaresan
Dhwani
RHS
= 1
=cos^2x+ sin^2x
=sinx+sin^2x. (Given that cos^2x=sinx)
=sinx(1+sinx)
=cos^2x(1+cos^2x) =LHS
Hence proved.
LIVE ONLINE CLASSES
Prepraring for the competition made easy just by live online class.
Full Live Access
Study Material
Live Doubts Solving
Daily Class Assignments
Other Related Questions on trigonometry
In ABC, if cot A+cot B+cot C = cosecA cosecB cosecC, then prove that ABC is right angle triangle.
In ABC, if cot A+cot B+cot C = cosecA cosecB cosecC, then prove that ABC is right angle triangle.
trigonometry
1 Answer Available
Last Activity: 3 Years ago
- Find the general solution of equation tan3β=cot2β
For all angles between -720 and +720
- Find the general solution of equation tan3β=cot2β
For all angles between -720 and +720
trigonometry
1 Answer Available
Last Activity: 3 Years ago
To prove : Cosec(45 degree - A)Cosec(45 degree + A) = 2SecA
To prove : Cosec(45 degree - A)Cosec(45 degree + A) = 2SecA
trigonometry
1 Answer Available
Last Activity: 3 Years ago
Derive a formula for the area of the triangle, given b, A, B, and C. That is, derive the formula: (b^2sinAsinC)/(2sinB)
Derive a formula for the area of the triangle, given b, A, B, and C. That is, derive the formula: (b^2sinAsinC)/(2sinB)
trigonometry
1 Answer Available
Last Activity: 3 Years ago
WHAT IS THE LIMIT WHEN X TOWARDS TO 0 OF sin6x/5x ? limπ₯β0 π ππ6π₯/5π₯
WHAT IS THE LIMIT WHEN X TOWARDS TO 0 OF sin6x/5x ? limπ₯β0 π ππ6π₯/5π₯
trigonometry
1 Answer Available
Last Activity: 3 Years ago