Question

Sin²a+cos²a +sin²a +cos²a÷ sin²a- cos²a

Answer 1

Step-by-step explanation:

$1 - \cos {}^{2} a + \cos {}^{2} a + 1 - \cos {}^{2} a + \cos {}^{2} a \div \sin {}^{2}a - 1 + \sin {}^{2}a \\ 2 \div 2 \sin {}^{2} a - 1 \\ 1 \div \cos {}^{2} a \\ \sec {}^{2} a$