Precalculus Examples

Evaluate log base 2 of 512
log2(512)log2(512)
Step 1
Rewrite as an equation.
log2(512)=xlog2(512)=x
Step 2
Rewrite log2(512)=xlog2(512)=x in exponential form using the definition of a logarithm. If xx and bb are positive real numbers and bb does not equal 11, then logb(x)=ylogb(x)=y is equivalent to by=xby=x.
2x=5122x=512
Step 3
Create equivalent expressions in the equation that all have equal bases.
2x=292x=29
Step 4
Since the bases are the same, the two expressions are only equal if the exponents are also equal.
x=9x=9
Step 5
The variable xx is equal to 99.
99
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 [x2  12  π  xdx ]  x2  12  π  xdx