INDICES
TIP: When doing these sort of problems, remember:
a) There
are several rules of using indices which apply to specific numbers and general
algebraic equations. You'll have to learn these, so
here they are:
xm x xn = xm+n (example 22 x 23 = 25, which is 2x2 x 2x2x2)
xm/xn = xm-n (example 22/23 = 2-1, which from the other rule below = ½)
(xm)n = xmn (example (22)3 = 22 x 3 = 26)
x0 = 1 (unless x = 0, then x0 = 0)
x1 = x (example 21 = 2)
x-n = 1/xn (example 2-1 = ½)
x½ = Öx (example 9 ½ = Ö9 = 3, this is a particular case of the next rule)
xm/n = nÖxm (example 82/3 = 3Öx2, i.e. the cubed root of 8 squared = 4)
Remember that these rules will apply when m and n are equal to any number.
b) It can
be difficult to learn rules like these, so the best thing to do is try solving
lots
of problems on indices. The more you do, the more
you will find that you have
naturally learned the rules anyway (this is the easy
way to learn them).
c) You will
need to know the rules of indices to solve all sorts of problems in algebra,
so
it's well worth learning the rules properly.
Solve the following:
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1. Simplify |
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2. Simplify |
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3. Simplify |
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4. Simplify |
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5. Simplify |
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6. If x = 38, express x½ in the form 3n where n is an integer. |
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7. a = 29 x 5-6 |
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8. Find the value of k where |