Page 52 - Trigonometry

Example 15
rd
A 3 polynomial has three roots which are,

tan(31.94), cos(102.85), −sin(64.28)

Determine the coefficients of the polynomial.

Let

= tan(31.94), = cos(102.85), = −sin(64.28)

Then

( − )( − )( − )

Expand,

2
[ − ( + ) + ]( − )
3
2
2
− − ( + ) + ( + ) + −
3
2
− ( + + ) + ( + + ) −
In your fx calculator, store the trigonometric values,
enter the following keystrokes,

l31.94)=q(STO)(A)
k102.85)=q(STO)(B)

zj64.28)=q(STO)(C)

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