Kąt α jest ostry i cosα=4/5. Wtedy sin^2 (90°-α) jest równy

$\displaystyle \frac{16}{25}$\displaystyle \frac{16}{25}

$\displaystyle \frac{9}{25}$\displaystyle \frac{9}{25}

$\displaystyle \frac{3}{5}$\displaystyle \frac{3}{5}

$\displaystyle \frac{4}{5}$\displaystyle \frac{4}{5}