I'm trying to calculate the cube root of -8, for example, so I type in these buttons:

8

CHS (change sign)

Enter

3

1/x

y^x

But it gives me an error. What is the correct way to go about doing this?

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- May 12th 2012, 02:10 PMdaigoHow do I calculate roots with the 15c?
I'm trying to calculate the cube root of -8, for example, so I type in these buttons:

8

CHS (change sign)

Enter

3

1/x

y^x

But it gives me an error. What is the correct way to go about doing this? - May 12th 2012, 02:13 PMMoebiusRe: How do I calculate roots with the 15c?
(-8)^(1/3) would suffice.

I'm not sure exactly how to put that in your calculator though. - May 12th 2012, 02:26 PMskeeterRe: How do I calculate roots with the 15c?
HP-15c power calculations from this owner's manual ...

http://hp15c.org/hp15c.pdf - May 12th 2012, 03:37 PMdaigoRe: How do I calculate roots with the 15c?
(-8)^(1/3) is exactly what I am doing in my original post. If you look at the picture in skeeter's attachment it is the exact steps I am doing.

Input 8,

CHS (change sign) to make (-8),

Enter to store the (-8),

Then input 3,

1/x to get the reciprocal of 3 which is (1/3),

y^x to raise (-8) (which is y) to the (1/3) power (which is x).

I don't get what I am doing wrong, it should make sense enough to calculate... - May 12th 2012, 03:42 PMMoebiusRe: How do I calculate roots with the 15c?
Have you tried calculating the positive root, (8)^(1/3)? If that works you can always calculate the positive roots and just add the negative sign.