Aproximation lg(n!)=n(lgn)-0.434)

89 Views Asked by At

I should use this approximation in order to find the value of this combination of 78 elements, class 19 without using a calculator. I have no idea how can I write n! in another way in order to use it. Please help me! Thanks! enter image description here

1

There are 1 best solutions below

0
On

$$y=\binom{78}{19}$$ $$=>y=\frac{78!}{19!\times59!}$$ $$=>\lg{y}=\lg{78!}-\lg{19!}+\lg{59!}$$

$$y=10^{\lg{78!}-\lg{19!}+\lg{59!}}$$

Now you can use the approximation formula to calculate the rest of it.