hitunglah nilai a! jika seperti gambar diatas ^

[tex] \frac{1 + \sin( \alpha ) }{ {cos}^{2} \alpha } = 1 \\ \frac{1 + \sin( \alpha ) }{1 - {sin}^{2} \alpha } = 1 \\ \frac{1 + \sin( \alpha ) }{(1 + sin \: \alpha )(1 - sin \: \alpha )} = 1 \\ \frac{1}{1 - sin \alpha } = 1 \\ 1 - sin \: \alpha = 1 \\ \sin( \alpha ) = 0 \\ \alpha = {0}^{o} [/tex]