Question 824927
If sin theta equals 2/5 and sec theta is less than 0, find cos theta and tan theta
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letx=theta
reference angle in quadrant II, in which cos and tan<0
cosx={{{-sqrt(1-sin^2(x))=-sqrt(1-4/25)=-sqrt(21/25)=-sqrt(21)/5)}}}
tanx=sinx/cosx=2/-&#8730;21=-2&#8730;21/21