Write true or false. 1. A decimal is a number that uses place value and a decimal point to
show part of a whole.

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).

How to do this , and can some one explain

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