What is the inequality of 2x+15 is greater then or equal to 45

To prove p is equal to q using an indirect proof what would your starting assumption be?

Find the gradient of f(x,y,z)equals=left parenthesis x squared plus y squared plus z squared right parenthesis superscript negative 1 divided by 2 baseline plus ln left parenthesis x right parenthesis x2+y2+z2−1/2+ln(xyz) at the point left parenthesis negative 2 comma 1 comma negative 2 right parenthesis(−2,1,−2).

The value √10 and √15 are plotted on the number line