As we learnt in Dividing Powers, when we divide index terms with like bases, we subtract the powers.
So what happens when we subtract and we are left with a power of 0? For example,
$4^1\div4^1$41÷41 | $=$= | $4^{1-1}$41−1 |
$=$= | $4^0$40 |
Let's write this division problem as a fraction:
$\frac{4^1}{4^1}=1$4141=1
You'll notice that the numerator and denominator are the same so the fraction simplifies to $1$1. Notice that this will also be the case with $\frac{4^2}{4^2}$4242 or any expression where we are dividing like bases whose indices (or powers) are the same.
So the result we arrive at by using index laws is $4^0$40, and the result we arrive at by simplifying fractions is $1$1This must mean that: $4^0=1$40=1
If we extend this to any other base, we get the result that
$x^0=1$x0=1
for any value of $x$x.
$x^0=1$x0=1
$\left(x+1\right)^0=1$(x+1)0=1
Similarly: $\left(5x\right)^0=1$(5x)0=1
If there are no brackets, then the index (or power) only applies to the number it is connected to:
$5\times x^0$5×x0 | $=$= | $5\times1$5×1 |
$=$= | $5$5 |
Simplify $705^0$7050
$705^0=1$7050=1
Simplify $\left(6a\right)^0$(6a)0.
Simplify $9\times\left(15x^6\right)^0$9×(15x6)0.