Practicing Success
If tan2A + 2tanA - 63 = 0 Given that 0 < A < $\frac{\pi}{2}$ what is the value of ( 2sinA + 5cosA)? |
$19\sqrt{50}$ $15\sqrt{50}$ $\frac{19}{\sqrt{50}}$ $\frac{15}{\sqrt{50}}$ |
$\frac{19}{\sqrt{50}}$ |
tan2A + 2tanA - 63 = 0 tan2A +9tanA - 7tanA - 63 = 0 on solving , tanA = \(\frac{7}{1}\) By using pythagoras theorem , P2 + B2 = H2 72 + 12 = H2 H = √50 Now , ( 2sinA + 5cosA) = 2 ( \(\frac{7}{√50}\) ) + 5 ( \(\frac{1}{√50}\) ) = \(\frac{19}{√50}\) |