Soln:
Prove that: (2cosA + 1)(2cosA - 1)(2cos2A - 1) = 2cos4A + 1
Prove that: (2cosA + 1)(2cosA - 1)(2cos2A - 1) = 2cos4A + 1
S.E.E. Solution
5.0
stars based on
35
reviews
Soln:
SUBSCRIBE TO OUR NEWSLETTER
You May Also Like
- Prove that: (sec^2A+1)(sec^4A+1)(sec^8A+1)=tan8A.cotA
Soln:
...
- Q. At the foot of the mountain, the elevation of its summit is 45 degree. After going up at a distance of 1km towards the top of the mountain at an angle of 30 degree, the elevation changes to 60 degree. Find the height of the mounatain.
Soln:
...
- Q. If A+B+C=pie and cosA=cosB.CosC. Prove that: tanA=tanB+tanC.
Soln:
R.H.S.
= tanB+tanC
= (sinB/cosB)+(sinC/cosC)
= (sinBcosC+cosBsinC)/(cosB.cosC)
= sin(B+C)/cosA & ...
- Q. If (-4,3) and (2,5) are pair of opposite vertices of a square. Find the equations of the diagonals of the square.
Soln:
The equation of diagonal BD is given by as,
y-y1 = (y2-y1)/(x2-x1)*(x-x1)
Here, x1 = -4, y1 = 3 and x2 = 2 ...
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
...
