Question

$1 \div \sqrt{2 } = cosx \: then \: find \: cos {?}^{2} x \: - sin {?}^{2} x = \:$
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Answer 1

Answer:

$1 \div \sqrt{2 } = cosx \: then \: find \: cos {?}^{2} x \: - sin {?}^{2} x = \:$