Question

Please answer question no 4 a​

Answer 1

Hëy Frïèñd...

Here is the Solution.

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In ∆BDC

BC² = BD² + DC²

BC² = 9² + 12²

BC² = 81 + 144

BC² = 225

BC = 15cm

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Now in ∆ABC

AC² = AB² + BC²

AB² = AC² - BC²

AB² = 25² - 15²

AB² = 625 - 225

AB² = 400

AB = 20

AB = 20 cm

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Therefore...

2 sin y - cos y

• $2 x \frac{BD}{BC} - \frac{DC}{BC}$

• $\frac{2x9}{15} - \frac{12}{15}$

• $\frac{18}{15} - \frac{12}{15}\\ \frac{18 - 12}{15} \\ \frac{6}{15} \\ \frac{2}{5}$...

Hence...

ANS. ${\bold{\frac{2}{5}}}$

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I Hope This Will Help You ^_^^_^