what is -a^-2 if a=-5?
A.)-25
B.)25
C.)-1/25
D.)1/25
I think it is D.
Please help.
a^-2 = 1/a^2, so
(C)
even though that is -a? you wrote it as positive a to the -2 power = 1/a to the 2nd ...just making sure
yes. the "-" is done after the ^-2
-a^-2 = -(a^-2) = -1/a^2
(-a)^-2 = 1/(-a)^2 = 1/a^2
Thank you for the explanation - that really helps....
To solve this problem, we need to substitute the value of "a" into the expression -a^-2 and simplify.
Given that a = -5, we can substitute -5 into the expression:
-a^-2 = -(-5)^-2
Next, we need to evaluate the exponent (-5)^-2. To do this, we remember that a negative exponent indicates taking the reciprocal of the number raised to that exponent.
So, (-5)^-2 becomes (-1/5)^2 because we take the reciprocal of -5 and square it:
(-1/5)^2 = (-1/5) * (-1/5) = 1/25
As a result, the value of -a^-2 when a = -5 is 1/25. Hence, the correct answer is D) 1/25.