Question

How to do this question sheathing the graph?

Answer 1

The equal exact values are `-1/sqrt2 = - 0.707106781...`
Graphical 7-sd approximations:`- 0.70710678...`

Explanation:

Graph to locate `f( - pi )` near `- 0.7`
graph{(y-sin(3(x+pi/4)))(x-pi +0.0000001y)(x+pi +0.0000001y)(y^2-1)=0}

Graph for 7-sd `f( - pi ) = - 0.7071068`

Also, 7-sd `f( pi ) = 0.7071068`
graph{(y-sin(3(x+pi/4)))(x+pi+0.00000001 y)=0[-3.1416 -3.14159 -0.707107107 -0.70710566]}
Note that

`f ( pi ) = sin ( 15/4pi ) = sin ( 4pi - pi/4 ) = - sin (pi/4) = - 1/sqrt2`.