How to add a step size of 2

Ok so i have a function to write and it is supposed to calculate and return the product of 1 to n in a step size of 2.

for n = 1:2
     inv(1*3*5*7);
end

How do i make this a step size of two? Do i do for n = 1:n:2?

[Star Strider]

The documentation on the colon(:) operator will get you started.

[Tony Hill]

ok i changed it to

For n = 1:n:2 and i keep getting a syntax error about variable n being used before it was assigned

[Star Strider]

You’re getting there.

From the documentation:

Using two colons to create a vector with arbitrary real increments between the elements,

E = 0:.1:.5

results in

E =
    0    0.1000    0.2000    0.3000    0.4000    0.5000

Answer 1

[Geoff Hayes]

Hi Tony,

Either type help for in the MATLAB command window to get information on for loop syntax, or visit the following link: for loop.

Geoff

Answer 2

[Image Analyst]

No for loop is needed at all. See the prod() function.

And you got the colon stuff in the wrong order. The correct order is startingValue : stepAmount : endingValue. You put the step at the end instead of the middle.

[Image Analyst]

Anyway, that problem is trivial, toddler-level stuff. Here's a far more interesting question for you:

Investigate these two different equations with different values of n:

sum1 = 1^n + 19^n + 20^n + 51^n + 57^n + 80^n + 82^n
sum2 = 2^n + 12^n + 31^n + 40^n + 69^n + 71^n + 85^n

Explain what you see and why you see it.