I’m stuck on number 2, 3 and 4

Show algebraically that f and g are inverse functions f(x)=x^2/-6; g(x)=square root of 2x+12

Find the equation of a line that is perpendicular to line g that contains (p, q). coordinate plane with line g that passes through the points negative 3 comma 6 and 0 comma 5 3x − y = 3p − q 3x + y = q − 3p x − y = p − q x + y = q − p

Which of the following pair(s) of circles have las a common external tangent? select all that apply. a and b a and c b and c