 Hello and welcome to the session. In this session we are going to discuss the following question and the question says that graph y is equal to minus x square plus 8x minus 13 on graphing calculator also find its vertex. Let us start with the solution of the given question. We have to graph the function y is equal to minus x square plus 8x minus 13 on graphing calculator. This is the TI 83 plus calculator. First we begin with home screen and press y is equal to button. This takes us to the equation entering screen where we will write our equation. Let us enter the equation minus x square plus 8x minus 13 into y1. For this we press negative sign and then we press x t theta n button. So minus x will appear on the screen then we press x square button. Now minus x square will appear on the screen then we press plus sign and then number 8 key and then multiplication sign then x t theta n key for x. So we get minus x square plus 8x and then we press minus sign and then number 1 key and then number 3 key. So we get the equation y1 is equal to minus x square plus 8x minus 13 to view its graph we press graph key. On the screen the graph of the quadratic function y is equal to minus x square plus 8x minus 13 will appear on the coordinate axis. We see that it is a downward facing parabola to know the coordinates of points lying on the graph we press trace key. The following screen will appear. This is the required graph of the given function. Now we want to find its vertex since it is a downward facing parabola so its maximum point will lie on vertex so we find its maximum point and its coordinate will be the vertex. For this we press second key followed by calculate key. Here we should note that calculate is written above trace key so we press this key. The following screen will appear. We want to find the maximum point of the graph so we scroll down to maximum that is number 4 and press enter that is this key or we can directly press 4 on the calculator. The following screen will appear. Now we see that left bound is written for the left bound choose any location to the left of the maximum point by pressing arrow keys and then press enter key. An anchor for left bound will appear and right bound will be asked. So for right bound we choose any location to the right of the maximum point and press enter key. So the following screen will appear showing both left and right anchors. Guests will appear on the screen. So now we again press enter key and the maximum point will appear. See we have got x is equal to 4.0000007 and y is equal to 3 so at x is equal to 4 and y is equal to 3 we have maximum point thus Vertex will be given by the ordered pair 4 3 this is the required answer. This completes our session hope you enjoyed this session.