Q.In triangle ABC, \(\angle C = 90^\circ\) and AC : BC = 3 : 4, then what is the value of cosec A? (a) \(\cfrac{3}{4}\) (b) \(\cfrac{5}{3}\) (c) \(\cfrac{5}{4}\) (d) \(\cfrac{3}{5}\)
Answer: C
Let \(AC = 3x\) and \(BC = 4x\) in \(\triangle ABC\) \(\therefore AB = \sqrt{AC^2 + BC^2}\) i.e., \(AB = \sqrt{9x^2 + 16x^2}\) i.e., \(AB = \sqrt{25x^2} = 5x\) \(cosec A = \cfrac{AB}{BC} = \cfrac{5x}{4x} = \cfrac{5}{4}\)
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