how to get this graph to plot correctly?

f(x) = x^8 − 5x^4 + e^x − 7

I've tried f=@(x)x.^8 - 5*x.^4 + exp(x) - 7; and setting x = [-5:0.1:5]; and then just using the plot function, but it doesnt seem right...

Answer 1

[Star Strider]

This works for me:

f=@(x)x.^8 - 5*x.^4 + exp(x) - 7;

x = [-5:0.1:5];

plot(x, f(x))

It is essentially your code. What ‘doesn’t seem right’ about the plot?

[MaraBoj]

if I type in the function on a graphing calculator the graph looks different than on matlab

[Star Strider]

Trust the MATLAB plot!

[MaraBoj]

haha okay thanks

[Star Strider]

My pleasure.

[Steven Lord]

You won't see much detail by default because the limits on the Y axis span a wide range of values. 5^8 is near 400000, while 0^8 is 0. You'd need to zoom into the plot or change the axis limits to see the detail for small values of x.

axis([-2 2 -20 20])