Home
Class 12
MATHS
Prove that sin18^@.cos36^@ = 1/4...

Prove that `sin18^@.cos36^@ = 1/4`

Text Solution

Verified by Experts

`Sin18^@ Cos36^@=(sqrt5-1)/4)((sqrt5+1)/4)=(5-1)/16=1/4`
Promotional Banner

Topper's Solved these Questions

  • THREE DIMENSIONAL GEOMETRY

    MBD PUBLICATION|Exercise QUESTION BANK|523 Videos

  • VECTORS

    MBD PUBLICATION|Exercise QUESTION BANK|138 Videos

Similar Questions

Explore conceptually related problems

Prove that sin^2(18)^@ + cos^2(36)^@ = 3/4

Prove that (cos9^@+sin9^@)/(cos9^@-sin9^@)=tan54^@

Prove that 8 sin10^@.sin50^@.sin70^@=1

Prove that int_0^(pi//4) cos^2 2x sin^3 4x dx=1/6

Prove that sin( cos^(-1) ""(3)/(5) + sin^(-1)""(5)/(13) ) = (63)/(65)

Prove that (d)/(dx)[(sin2x+1/(cos^2x)]

Prove that sin^-1(4/5)+ sin^-1(5/13)+ sin^-1(16/65)= pi/2

Prove that 4sinAsin(60^@-A)sin(60^@+A)-sin3A=0

Prove that sin^(-1)((3)/(5)) + sin^(-1)((8)/(17)) = cos^(-1)((36)/(85)) .

Prove the following : cos36^@.cos72^@.cos108^@.cos144^@ = 1/16