Editing Slide rule (section)

====Roots and powers====
There are single-decade (C and D), double-decade (A and B), and triple-decade (K) scales. To compute <math>x^2</math>, for example, locate x on the D scale and read its square on the A scale. Inverting this process allows square roots to be found, and similarly for the powers 3, 1/3, 2/3, and 3/2. Care must be taken when the base, x, is found in more than one place on its scale. For instance, there are two nines on the A scale; to find the square root of nine, use the first one; the second one gives the square root of 90.

For <math>x^y</math> problems, use the LL scales. When several LL scales are present, use the one with ''x'' on it. First, align the leftmost 1 on the C scale with x on the LL scale. Then, find ''y'' on the C scale and go down to the LL scale with ''x'' on it. That scale will indicate the answer. If ''y'' is "off the scale", locate <math>x^{y/2}</math> and square it using the A and B scales as described above. Alternatively, use the rightmost 1 on the C scale, and read the answer off the next higher LL scale. For example, aligning the rightmost 1 on the C scale with 2 on the LL2 scale, 3 on the C scale lines up with 8 on the LL3 scale.

To extract a cube root using a slide rule with only C/D and A/B scales, align 1 on the B cursor with the base number on the A scale (taking care as always to distinguish between the lower and upper halves of the A scale). Slide the slide until the number on the D scale which is against 1 on the C cursor is the same as the number on the B cursor which is against the base number on the A scale. (Examples: A 8, B 2, C 1, D 2; A 27, B 3, C 1, D 3.)