HELP ASAP IM SO CONFUSED

Which is the focus of a parabola with equation y2=4x

In the diagram, ab is tangent to c, ab = 4 inches, and ad = 2 inches. find the radius of the circle.

Type the correct answer in each box. use numerals instead of words. if necessary, use / for the fraction bar(s). line m has no y-intercept, and its x-intercept is (3, 0). line n has no x-intercept, and its y-intercept is (0, -4). the equation of line m is , and the equation of line n is .