How to plot a function is equal to a constant?

I am new to MATLAB and am trying to graph ln(x^2)=0.7 to find the roots graphically. I have tried to following.

x=-5:5;
y=log(x.^2)-0.7;
plot (x,y)

this gets me close but the graph isn't coming out right. I also tried to y=log(x.^2)=0.7 or y=log(x.^2)-0.7=0 but this doesn't work either. Any help is appreciated!

Answer 1

[Roger Stafford]

The range for x = -5:5 includes the value x = 0 for which log(0) is minus infinity. I would suggest

   x = linspace(1,2,1000);
   y = log(x.^2)-.7;
   plot(x,y)

Look for where it crosses y = 0.

Of course there is a much easier method:

   x = sqrt(exp(0.7));

Answer 2

[John]

I got it to work by using ezplot('(log(x.^2)-0.7)'). Thank you though!