Use the quotient and reciprocal identities to find tanθ\displaystyle {\tan{\theta}} exactly given:

cosθ=317\displaystyle {\cos{\theta}}=\frac{{3}}{{17}}

sinθ=27017\displaystyle {\sin{\theta}}=\frac{{{2}\sqrt{{{70}}}}}{{17}}

 tanθ=\displaystyle {\tan{\theta}}=