## anonymous one year ago how you knew whether to use a positive or a negative exponent.

1. anonymous

how old are you?

2. anonymous

what math class? :)

3. anonymous

@zzr0ck3r

4. zzr0ck3r

it depends. A negative exponent, just means put it all under 1 and make the exponent positive. $$2^{-1}=\dfrac{1}{2^1}=\dfrac{1}{2}$$ $$3^{-4}=\frac{1}{3^4}$$ Make sense?

5. anonymous

so if i wanted to change this into a scientific notation how would i determine if it was negative or positive?

6. anonymous

131,000,000 ft.

7. anonymous

8. anonymous

8th :)

9. anonymous

if you move from left the exponent is positive from right, negative

10. anonymous

is this from chemistry?

11. zzr0ck3r

$$0.0003896=3.896\times 10^{-4}$$ $$3896000=3.896\times 10^6$$

12. anonymous

no this was the question i had The circumference of the Earth is approximately 131,000,000 ft. a. Write this number in scientific notation and tell how you knew whether to use a positive or a negative exponent.

13. zzr0ck3r

$$131000000=1.31\times 10^8$$ We want it so that there is only one number before the decimal. Since we need to move it left $$6$$ times we get a positive $$6$$.

14. anonymous

15. anonymous

ohhh ok thank you soo much for helping me!:D

16. zzr0ck3r

no problem.

17. zzr0ck3r

that $$6$$ shuold be an $$8$$..

18. anonymous

gotcha :)