Home
Class 12
MATHS
Show that,cos^(2)alpha + cos^(2) (120^(@...

Show that,`cos^(2)alpha + cos^(2) (120^(@) - alpha) + cos^(2) (120^(@) + alpha) = 3/2.`

Text Solution

Verified by Experts

The correct Answer is:
`=3/2 (cos^(2)alpha + sin^(2)alpha) = 3/2`
Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRIC RATIOS OF COMPOUND ANGLES

    CHHAYA PUBLICATION|Exercise Multiple Choice Type Questions|12 Videos

  • TRIGONOMETRIC RATIOS OF COMPOUND ANGLES

    CHHAYA PUBLICATION|Exercise Very Short Answer type Questions|23 Videos

  • TRIGONOMETRIC RATIOS OF ASSOCIATED ANGLES

    CHHAYA PUBLICATION|Exercise SAMPLE QUESTIONS FOR COMPETITIVE EXAMS - ASSERTION-REASON TYPE|2 Videos

  • TRIGONOMETRIC RATIOS OF MULTIPLE ANGLES

    CHHAYA PUBLICATION|Exercise Comprehension Type|6 Videos

Similar Questions

Explore conceptually related problems

Prove that, sin^(2) alpha + sin^(2) (120^(@) - alpha) + sin^(2) (120^(@) + alpha) = 3/2

Prove that, cos^(3) alpha + cos^(3) (120^(@) + alpha) + cos^(3) (240^(@) + alpha) = 3/4 cos 3 alpha

Prove that, cos alpha + cos(120^(@) + alpha) + cos (120^(@) - alpha) = 0

Prove that cos alpha cos (120^(@) + alpha) cos (240^(@) + alpha) = 1/4 cos 3 alpha

Prove that cos^2alpha+cos^2(120^@-alpha)+cos^2(120^@+alpha)=3/2

Prove that : sec alpha+ sec (120^(@)+ alpha) sec (120^(@)-alpha)=-3 sec 3 alpha

Calculate the value of (sin^(6)alpha +cos^(6) alpha + 3sin^(2) alpha cos^(2) alpha).

Find the sum to n terms of the following series: cos alpha + cos (pi - alpha) + cos (2pi + alpha) + .......(0 < alpha < (pi)/2) .

Prove that (cos alpha - cos beta)^(2) +(sin alpha - sin beta)^(2) = 4 "sin"^(2) (alpha-beta)/2

"Show that :" 2 sin^(2) beta + 4 cos ( alpha + beta) sin alpha sin beta + cos2 (alpha + beta) = cos2 alpha