The left hand rule is an approximate method for finding the area under the curve f(x) between the limits x=a and x = b which uses the formula:

\qquad \displaystyle \int_a^b f(x) \, dx = h(f(x_0) + f(x_1) + ... + f(x_{n-1}))

where x_0, x_1,... x_{n-1} \, are the values of x at the left hand end of n strips, each of width h

\qquad \displaystyle \int_a^b f(x) \, dx = h(f(x_0) + f(x_1) + ... + f(x_{n-1}))

where x_0, x_1,... x_{n-1} \, are the values of x at the left hand end of n strips, each of width h

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## Glossary

### rule

A method for connecting one value with another.