What is the length of dk? 7.0 3.5 8.5 12.7

Can someone check if i did this correct. it’s number 4 if you’re wondering.

What is the frequency of the sinusoidal graph?

Acylinder with a base diameter of x units has a volume of jxcubic units which statements about the cylinder are true? check all that apply. the radius of the cylinder is 2 x units. the radius of the cylinder is 2x units. the area of the cylinder's base is 200 square units. the area of the cylinder's base is a square units. the height of the cylinder is 2x units. the height of the cylinder is 4x units. mark this and return save and exit next submit