Practice problem
Simplify the expression cos2(9x)−sin2(9x)\\\cos^2(9x)-\sin^2(9x)cos2(9x)−sin2(9x)
tan(18x)\tan(18x)tan(18x)
cos(9x)\cos(9x)cos(9x)
sin(18x)\sin(18x)sin(18x)
cos(18x)\cos(18x)cos(18x)
Type a concept, like “slope” or “photosynthesis”.