# Math exponent in C language.

#### Lilian23

Joined Oct 7, 2008
12
Hi!

How would you write this in C?

y = -8E-11x^5

I am aware of the pow() function but that takes things like 4^5, 2^3, etc. What about a very small number like that to the fifth power? Is there something for "E"? my compiler does not like it if I put -.00000000008

thanks

#### mik3

Joined Feb 4, 2008
4,843
The length of the number you put depends if it is unsigned or singed and if you define it as short, long, longlong or floating.

As, i understood you are talking about PIC uC programming so check its C reference manual here on page 198:

#### mnwcsult

Joined Oct 29, 2008
1
Hi!

How would you write this in C?

y = -8E-11x^5

I am aware of the pow() function but that takes things like 4^5, 2^3, etc. What about a very small number like that to the fifth power? Is there something for "E"? my compiler does not like it if I put -.00000000008

thanks

y = pow(-8.0E-11, 5.0);

FYI, you really should have just looked this up.

#### chuka_709

Joined Nov 2, 2008
1
Hi all,
a0=a1=1; ai=a(i-2)+a(i-1)/pow(2,i-1); i=2,3,... so
a0*a1*...*a14=?
how would you write this in C?

Plz help me and Thx