The figure ABCD has four sides, and its vertices lie on a circle. This situation has a specific name: cyclic quadrilateral. This situation also has a specific theorem associated to it: Opposite angles of a cyclic quadrilateral are supplementary. Let's use this theorem to our advantage:
\(m\angle A+m\angle C=180^{\circ}\) | Substitute in the known expressions for both of these angles. |
\(3x+6+x+2=180\) | Now, simplify the left-hand side as much as possible. |
\(4x+8=180\) | Now, use algebraic manipulation to isolate the variable. |
\(4x=172\) | |
\(x=43\) | Now, find the measure of the missing angle. |
\(m\angle A=3x+6\) | Substitute in the known value for x. |
\(m\angle A=3*43+6\) | Simplify. |
\(m\angle A=135^{\circ}\) |
To find f( g(3) ) , first let's find g(3) .
g(x) = x - 2_____ | Plug in 3 for x |
g(3) = 3 - 2 | Simplify. |
g(3) = 1 |
Since g(3) = 1 , we can substitute 1 in for g(3) .
f( g(3) ) = f( 1 )
Now we just have to find f(1) .
f(x) = 2x2 - 3_____ | Plug in 1 for x |
f(1) = 2(1)2 - 3 | Simplify. |
f(1) = 2(1) - 3 | |
f(1) = 2 - 3 | |
f(1) = -1 |
So....
f( g(3) ) = f(1) = -1
f( g(3) ) = -1