# How do i replicate power function? in MATLAB

## Homework Statement

need to do a power function of any number to any power WITHOUT using the power key

aka i need to replicate the power function using only loops and multiplication

for example, compute 5 to the third power by doing 5*5*5 not 5^3

but i don't know how to tell matlab to multiply a number by itself n times

for loops

## The Attempt at a Solution

Code:
num = input(' value? ')
n = input( ' power? ')
for num = 1:n
num = num*num;
end
disp(num)

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Mark44
Mentor
Try this. Note that it is a bad idea to use the same variable for both input and as a loop counter. This is why I changed the loop counter variable to i.
Code:
num = input(' value? ')
n = input( ' power? ')
product = 1
for i = 1:n
product = product*num;
end
disp(product)
Using your example numbers of num = 5 and n = 3 (to get 53), you get these values for product:
product = 1 (before start of loop)
product = 5 (when i = 1)
product = 25 (when i = 2)
product = 125 (when i = 3)

CEL
a^b = exp(b*log(a))

Mark44
Mentor
a^b = exp(b*log(a))
True (sort of), but not relevant to this problem. log on the right side above should be ln, the natural log.

physizl said:
aka i need to replicate the power function using only loops and multiplication

CEL
True (sort of), but not relevant to this problem. log on the right side above should be ln, the natural log.