ABC is a right-angled triangle.
AC = 8cm.
BC 15cm
Calculate the length of AB.

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

What is the length of the segment, endpoints of which are intersections of parabolas y=x2? 11 4 x? 7 4 and y=? 7 8 x2+x+ 31 8 ?

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)