Selanjutnya kak, Mengapa Tan kuadrat alfa+1 =sec kuadrat alfa?

[tex] {tan}^{2} a + 1= {sec}^{2} a \\ \frac{ {sin}^{2}a }{ {cos}^{2}a } + \frac{{cos}^{2}a}{{cos}^{2}a} = {sec}^{2} a \\ \frac{{sin}^{2}a + {cos}^{2}a}{{cos}^{2}a} = \frac{1}{{cos}^{2}a} = {sec}^{2} a[/tex]