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Building Approximations for Sin(x)

Age 16 to 18
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As a brute force approach you can choose 4 values of x, work out sin(x) and then solve the 4 simultaneous equations in 4 variables. This will give a polynomial which matches the values for your choices of x.

However, you can save time by noting the symmetry properties of sin(x), in that sin(-x) = - sin(x).

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The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

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