SSC Sample Paper Mock Test-7 SSC CGL Tear-II Paper-1

  • question_answer
    If \[\sec \theta =13/5,\] then what is the value of \[\frac{2\sin \theta -3cos\theta }{4\sin \theta -9\cos \theta }=?\]

    A)  1

    B)  2     

    C)  3

    D)  4

    Correct Answer: C

    Solution :

    Given, \[\sec \theta =\frac{13}{15}\]\[\Rightarrow \]\[{{\sec }^{2}}\theta =\frac{169}{25}\]
    \[\Rightarrow \]\[1+{{\tan }^{2}}\theta =\frac{169}{25}\]\[\Rightarrow \]\[{{\tan }^{2}}\theta =\frac{169}{25}-1\]
    \[\Rightarrow \]\[{{\tan }^{2}}\theta =\frac{144}{25}\]
    \[\Rightarrow \]   \[\tan \theta =\frac{12}{5}\]                   ?(i)
    \[\therefore \]      \[\frac{2\sin \theta -3\cos \theta }{4\sin \theta -9\cos \theta }=\frac{2\cdot \frac{\sin \theta }{\cos \theta }-3}{4\cdot \frac{\sin \theta }{\cos \theta }-9}\]
    \[=\frac{2\tan \theta -3}{4\tan \theta -9}=\frac{2\left( \frac{12}{5} \right)-3}{4\left( \frac{12}{5} \right)-9}\] [from Eq. (i)]
    \[=\frac{24-15}{48-45}=\frac{9}{3}=3\]


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