Soln:
Prove that: sin6.sin42.sin66.sin78 = 1/16
Soln:
Prove that: sin6.sin42.sin66.sin78 = 1/16
S.E.E. Solution
5.0
stars based on
35
reviews
Soln:
SUBSCRIBE TO OUR NEWSLETTER
You May Also Like
- Q. Evaluate: Cos6° × sin24° × cos72°
Soln:
Cos6° × sin24° × cos72°
= (1/2) * 2 Cos6° × sin24° × cos72°
= (1/2) [sin(6+24) – sin(6-24)] * cos72
= (1/2) ...
- Prove that: [tan(alpha)+sec(alpha)-1]/[tan(alpha)-sec(alpha)+1] = [1+sin(alpha)]/cos(alpha)
Soln
...
Prove that: cos^2(A+120)+cos^2(A-120)+cos^2(A) = 3/2
Soln:
Use formula:
cos2A = 2cos^2(A) - 1
cos2A+1= 2cos^2(A)
(1+cos2A)/2 = cos^2(A)
i.e. cos^2(A) = (1+cos2A)/2
... - Prove that: (sec^2A+1)(sec^4A+1)(sec^8A+1)=tan8A.cotA
Soln:
...
- If A, B, C and D are angles of a quadrilateral and sin(A/2).sin(B/2).Sin(C/2).sin(D/2) = 1/4, prove that A = B = C = D = pi/2
Soln:
...
