Question

if a is equal to b is equal to 45 a minus b is equal to sin a cos b minus cos a sin b
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Answer 1

given: A=45°, B=30°

sinAcosB-cosAsinB = sin45° × cos30° - cos45° × sin30°

note: sin45°=1/√2, sin30°=1/2, cos45°=1/√2, cos30°=√3/2

1/√2 × √3/2 - 1/√2 ×1/2

=> √3/2√2 - 1/2√2 =√3-1/2√2

rationalising the denominator

√3-1/2√2 × 2√2/2√2 = 2√6/8