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More Trigonometric Identities

Problems

Sums and Differences of Functions

How to Cite This SparkNote

Problem : Express the following as a sum or difference: sin(56)cos(42) .

sin(56)cos(42) = (sin(56 + 42) + sin(56 - 42)) = (sin(98) + sin(14)) .

Problem : Express the following as a sum or difference: cos(115)cos(60) .

cos(115)cos(60) = (cos(115 + 60) + cos(115 - 60)) = (cos(175) + cos(55)) .

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