What is the derivative of #y = 2x^2 - 5#?

2 Answers
Mar 6, 2018

The derivative is #4x#.

Explanation:

For this, we can use the power rule: #\frac d dx ax^n = nax^(n-1)#.

So, if we have #y=2x^2 -5#, the only term that involves an x is the #2x^2#, so that is the only term we have to find the derivative of. (The derivative of a constant such as #-5# will always be 0, so we don't have to worry about it since adding or subtracting 0 won't change our overall derivative.)

Following the power rule, #\frac d dx 2x^2 = 2(2)x^(2-1) = 4x #.

Mar 6, 2018

4x

Explanation:

the power rule goes as

#d/dx c*x^n = n*c*x^(n-1)#

#2x^2 - 5#

#= 2x^2 - 5x^0#

the 2 and 0 comes down to the front and you subtract one from the power

=
#2*2x^(2-1) - 0*5*x^(0-1)#

=
#4x#
=

and that's it