Tolong bantu jawabb yaa

[tex] \tan(x) = \frac{1}{a} \\ r = \sqrt{ {a}^{2} + {1}^{2} } \\ r = \sqrt{ {a}^{2} + 1 } \\ \cos(x) = \frac{a}{ \sqrt{ {a}^{2} + 1 } } \\ \sin(x) = \frac{1}{ \sqrt{ {a}^{2} + 1 } } \\ \\ \cos(90 - x) = \cos(90) \cos(x) + \sin(90) \sin(x) \\ \cos(90 - x) = (0)( \frac{a}{ \sqrt{ {a}^{2} + 1 } } ) + (1)( \frac{1}{ \sqrt{ {a}^{2} + 1 } } ) \\ \cos(90 - x) = 0 + \frac{1}{ \sqrt{ {a}^{2} + 1} } \\ \cos(90 - x) = \frac{1}{ \sqrt{ {a}^{2} + 1} } [/tex]

jadi jawabannya A
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