Acircle k(o) with the radius r is given. line ab tangent to circle k(o) at b. find ab, if oa= 2 cm, and r=1.5 cm.

If given an equation of a line such as -1/2x+6 how would you create an equation of a line parallel and perpendicula to this line that goes through another point such as (4,10)

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).