Question

1) 4+5tg^2x * cos^2x , если sinx = 1/√5

Answer 1

$4 + 5 times frac{ { sin(x) }^{2} }{ { cos(x) }^{2} } times { cos(x) }^{2} = \ 4 + 5 { sin(x) }^{2} = \ 4 + 5( { frac{1}{ sqrt{5} } })^{2} = 5$