Odpowiedź :
[tex]a) sin\alpha = \frac{7}{25} \\ sin^{2} \alpha + cos^{2} \alpha =1\\(\frac{7}{25} )^{2} + cos^{2} \alpha =1 \\1- \frac{49}{625}= cos^{2} \alpha \\cos^{2} \alpha = \frac{576}{625}\\cos\alpha = \frac{24}{25}\\\\tg\alpha = \frac{sin\alpha }{cos\alpha } \\tg\alpha = \frac{7}{25} : \frac{24}{25}\\tg\alpha = \frac{7}{25} * \frac{25}{24} <--- tutaj skracasz 25 ze soba\\tg\alpha = \frac{7}{24} \\ctg\alpha = \frac{1}{tg\alpha } \\ctg\alpha = \frac{24}{7} \\------\\[/tex][tex]1= sin ^{2} \alpha + cos^{2} \alpha \\-9 * sin^{2} \alpha = cos^{2} \alpha \\1= sin^{2} \alpha + (-9sin^{2} \alpha)\\1= sin^{2} \alpha -9sin^{2} \alpha \\1= -8sin^{2} \alpha \\-1=8sin^{2} \alpha \\sin^{2} \alpha = \frac{1}{8} \\sin\alpha = \frac{{1} }{2\sqrt{2} }=\frac{\sqrt{2} }{8} \\-9 * \frac{1}{8}= cos^{2} \alpha \\cos^{2} \alpha = \frac{9}{8} \\cos\alpha = -\frac{3}{2\sqrt{2} } = -\frac{3\sqrt{2} }{8}[/tex]
[tex]b) tg\alpha = -\frac{1}{3} \\ctg\alpha = \frac{1}{tg\alpha } \\ctg\alpha = -3\\ctg\alpha = \frac{cos\alpha }{sin\alpha } \\-3= \frac{cos\alpha }{sin\alpha } \\-3 * sin\alpha = cos\alpha \\\\\\[/tex]
to co jest po prawej stronie jest do b ciag dalszy, piszesz od gory do dolu po czym przechodzisz na prawo jakby co