Question

Cпростите вираз дуже срочно треба
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Answer 1

$({{sin}frac{5pi}{2} {cos}a + cos frac{5pi}{2} sina})^{2} \ = ({sin(2pi + frac{pi}{2} )cosa + cos(2pi + frac{pi}{2} )sina }) ^{2} \ = ({1 times cosa + 0 times sina} )^{2} \ = {cos}^{2} a$