Question

Prove that sin 34°+cos64°-cos4

Answer 1

Sin34° + Cos64° - Cos4°

= Sin34° + Cos(34 + 30)° - Cos(34 - 30)°

= Sin34° + (-2Sin34°Sin30°)

= Sin34° - 2 × Sin34° × 1/2

= Sin34° - Sin34°

= 0

Hence Proved

Answer 2

Answer: 0

Step-by-step explanation:

sin 34°+cos 64°- cos 4

=sin34°+cos(34+30)°-cos(34-30)

= sin 34°+(-2sin34°sin30°

= sin34°-2×sin34°×1/2

= sin34°-sin34°

= 0

Hence proved