If cos=(-5/13), #tan theta > 0#, what is #sin theta#?

Question

9310 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-06-27T04:52:42

#sintheta=-12/13#

If #costheta<0# and #tantheta>0#

then #theta# is in the third quadrant, where #sintheta<0#

#sintheta=-sqrt(1-cos^2theta)#

#sintheta=-sqrt(1-(5/13)^2)#

#sintheta=-sqrt(1-25/169)#

#sintheta=-sqrt(144/169)#

#sintheta=-12/13#