Evaluating a function with Matlab

Hello friends,

Can anyone help me figure out why I am getting an imaginary number in the following code:

I am supposed to get 1.36. I have done the same calculation using my scientific calculator and symbolab and cannot find what the error is in my code.

[KSSV]

t = 10 ;
f = -((t-16.82)/5.604)^1.576

f = -0.3223 + 1.3241i

The result is clear, you are taking exponent of a negative number.

Answer 1

[Stephen23]

"Can anyone help me figure out why I am getting an imaginary number in the following code:"

Because you are taking the power of a negative number.

"I am supposed to get 1.36."

The simple, effiicient, MATLAB approach is to use REALPOW:

t = 10 ;
f = realpow(-((t-16.82)/5.604),1.576)

f = 1.3627

[Danny Guana]

Many thanks, I understood

Answer 2

[Torsten]

Then you have to program it as

t = 10;
f = sign(t-16.82).*abs((t-16.82)/5.604).^1.576

An expression

x^a 

for x<0 is complex-valued.

[Danny Guana]

Thanks a lot Torsten