1. Suppose that $\frac{\pi}{2} < t < \pi$, and that $\displaystyle \csc t=2$ . Find the values of the trigonometric functions $\sin(t)$, $\cos(t)$, and $\tan(t)$.

    $\displaystyle \left[ \sin t={{\sqrt{3}}\over{2}} , \cos t={{1}\over{2}} , \tan t=
\sqrt{3} \right] $

    $\displaystyle \left[ \sin t={{1}\over{2}} , \cos t=-{{\sqrt{3}}\over{2}} , \tan t=
-{{1}\over{\sqrt{3}}} \right] $

    $\displaystyle \left[ \sin t=-{{\sqrt{3}}\over{2}} , \cos t={{1}\over{2}} , \tan t=
-\sqrt{3} \right] $

    $\displaystyle \left[ \sin t={{1}\over{2}} , \cos t={{\sqrt{3}}\over{2}} , \tan t=
{{1}\over{\sqrt{3}}} \right] $

  2. Choose the correct trigonometric identity.

    $\displaystyle -\sin x\,\tan x-\cos x=2\,\cos x-\sec x$

    $\displaystyle -\sin x\,\tan x-\cos x=\sec x$

    $\displaystyle -\sin x\,\tan x-\cos x=-\sec x$

    $\displaystyle -\sin x\,\tan x-\cos x={{2\,\sec x}\over{\left(\csc x\right)^2}}-
\sec x$

  3. Choose the correct trigonometric identity.

    $\displaystyle \left(\sin ^2t+1\right)\,\left(1-\tan ^2t\right)=1$

    $\displaystyle \left(\sin ^2t+1\right)\,\left(1-\tan ^2t\right)=-{{2\,\sin ^4t+
\sin ^2t-1}\over{\cos ^2t}}$

    $\displaystyle \left(\sin ^2t+1\right)\,\left(1-\tan ^2t\right)={{\sin ^2t+1
}\over{\cos ^2t}}$

    $\displaystyle \left(\sin ^2t+1\right)\,\left(1-\tan ^2t\right)=2\,\cos ^2t-1$

  4. Find the derivative $f'(x)$ for $f(x) =\displaystyle -3\,\csc x-2\,\cos x $ .

    $f'(x) =\displaystyle -2\,\sin x-3\,\sec x $ $f'(x) =\displaystyle 3\,\sec x\,\tan x+2\,\cos x $ $f'(x) =\displaystyle -2\,\sin x-3\,\cot x\,\csc x $ $f'(x) =\displaystyle -3\,\sec x\,\tan x-2\,\cos x $ $f'(x) =\displaystyle 2\,\sin x+3\,\cot x\,\csc x $

  5. Suppose that $\displaystyle g\left( {{4\,\pi}\over{3}} \right) = 3 $ and $\displaystyle g'\left( {{4\,\pi}\over{3}} \right) = 2 $. Then find the derivative $\displaystyle f'\left( {{4\,\pi}\over{3}} \right)$ for $f(x) = \displaystyle g\left(x\right)\,\sin x $ .

    2 $\displaystyle {{3}\over{2}}-\sqrt{3}$ $\displaystyle -{{3^{{{3}\over{2}}}}\over{2}}$ $\displaystyle -\sqrt{3}-{{3}\over{2}}$ $\displaystyle \sqrt{3}-{{3}\over{2}}$

  6. Suppose that $0 < t < \frac{\pi}{2}$, and that $\displaystyle \csc t=4$ . Find the values of the trigonometric functions $\sin(t)$, $\cos(t)$, and $\tan(t)$.

    $\displaystyle \left[ \sin t={{\sqrt{15}}\over{4}} , \cos t={{1}\over{4}} , \tan t=
\sqrt{15} \right] $

    $\displaystyle \left[ \sin t=-{{1}\over{15}} , \cos t={{1}\over{4}} , \tan t=-{{4
}\over{15}} \right] $

    $\displaystyle \left[ \sin t={{1}\over{4}} , \cos t=-{{1}\over{15}} , \tan t=-{{15
}\over{4}} \right] $

    $\displaystyle \left[ \sin t={{1}\over{4}} , \cos t={{\sqrt{15}}\over{4}} , \tan t=
{{1}\over{\sqrt{15}}} \right] $

  7. Find the derivative $f'(x)$ for $f(x) =\displaystyle e^{x}\,\sec x $ .

    $f'(x) =\displaystyle e^{x}\,\sec x\,\left(\tan x+1\right) $ $f'(x) =\displaystyle -e^{x}\,\left(\cot x-1\right)\,\csc x $ $f'(x) =\displaystyle -e^{x}\,\sec x\,\left(\tan x+1\right) $ $f'(x) =\displaystyle e^{x}\,\left(\cot x-1\right)\,\csc x $

  8. Choose the correct trigonometric identity.

    $\displaystyle -{{\sin \left(2\,t\right)}\over{\cos \left(2\,t\right)+1}}=-\tan t$

    $\displaystyle -{{\sin \left(2\,t\right)}\over{\cos \left(2\,t\right)+1}}=\tan t$

    $\displaystyle -{{\sin \left(2\,t\right)}\over{\cos \left(2\,t\right)+1}}=\cot t$

    $\displaystyle -{{\sin \left(2\,t\right)}\over{\cos \left(2\,t\right)+1}}=-\cot t$

  9. Find the values of $\displaystyle \sin t$ and $\displaystyle \cos t$ for $\displaystyle t={{5\,\pi}\over{4}}$ .

    $\displaystyle \left[ \sin t={{1}\over{\sqrt{2}}} , \cos t={{1}\over{\sqrt{2}}}
\right] $

    $\displaystyle \left[ \sin t=-{{1}\over{\sqrt{2}}} , \cos t={{1}\over{\sqrt{2}}}
\right] $

    $\displaystyle \left[ \sin t={{1}\over{\sqrt{2}}} , \cos t=-{{1}\over{\sqrt{2}}}
\right] $

    $\displaystyle \left[ \sin t=-{{1}\over{\sqrt{2}}} , \cos t=-{{1}\over{\sqrt{2}}}
\right] $

  10. Choose the correct trigonometric identity.

    $\sin( t-{{\pi}\over{2}}) =
-\sin t$

    $\sin( t-{{\pi}\over{2}}) =
\sin t$

    $\sin( t-{{\pi}\over{2}}) =
\cos t$

    $\sin( t-{{\pi}\over{2}}) =
-\cos t$



Department of Mathematics
Last modified: 2025-08-29