We are given the equation:
a sin 15° + b cos 15° = √2 sin 15° cos 15°
Step 1: Express sin 15° cos 15° in a simpler form
Using the identity:
sin A cos B = 1/2 [sin (A + B) + sin (A - B)]
For A = B = 15°:
sin 15° cos 15° = 1/2 [sin (30°) + sin (0°)]
= 1/2 [1/2 + 0]
= 1/2 × 1/2
= 1/4
Thus, our equation becomes:
a sin 15° + b cos 15° = √2 × 1/4
a sin 15° + b cos 15° = √2 / 4
Step 2: Compare Coefficients
The given equation must hold for all values of 15°. This means we can compare the coefficients of sin 15° and cos 15° on both sides.
Since there is no sin 15° term on the right-hand side, its coefficient must be 0:
a = 0
For cos 15°:
b = √2 / 4
Step 3: Conclusion
Thus, the values of a and b are:
a = 0
b = √2 / 4
