Tolong dibantu yaa kawan..
Matematika
AdindaDwi671
Pertanyaan
Tolong dibantu yaa kawan..
1 Jawaban
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1. Jawaban whongaliem
[tex] sin^{2} x + cos^{2} x = 1[/tex]
[tex] (\frac{1}{5} \sqrt{5} ) ^{2} + cos^{2} x = 1[/tex]
[tex] \frac{ 1}{5} + cos^{2} x = 1[/tex]
[tex] cos^{2} x = 1 - \frac{1}{5} [/tex]
[tex] cos^{2} x = \frac{4}{5} [/tex]
[tex]cos x = \sqrt{ \frac{4}{5} } = \frac{2}{5} \sqrt{5} [/tex]
cos x - 5.cos (π/2 + x) - 2.sin (π + x) = cos x - 5.(- sin x) - ( - 2.sin x)
= cos x + 5.sin x + 2.sin x
= cos x + 7.sin x
= (2/5)√5 + 7 .(1/5)√5
= (2/5)√5 + (7/5)√5
= (9/5)√5