What is the axis of symmetry for the function f(x)=7−4x+x2? x = –3
x = –2
x = 2
x = 3

x = 2

Step-by-step explanation:

The vertex form of the parabola is given by  

Comparing this equation with vertex form of a parabola , where (h,k) is the vertex

h = 2

k = 3

Hence, vertex is (2,3)

Now, axis of symmetry of a parabola passes through the vertex and divide the parabola in two equal halves.

Hence, axis of symmetry of the parabola is given by

x = h

x = 2

Third option is correct.

m∠a is 90°

m∠b is 40°