Lutasin ang cospi/7+cos2pi/7+cos3pi/7+cos4pi/7+cosfrac{5pi}{7}+cosfrac{6pi}{7}=

$$\cos \frac { \pi } { 7 } + \cos \frac { 2 \pi } { 7 } + \cos \frac { 3 \pi } { 7 } + \cos \frac { 4 \pi } { 7 } + \cos \frac { 5 \pi } { 7 } + \cos \frac { 6 \pi } { 7 } =$$

I-evaluate

$$0.00000000000000031$$

Mga Hakbang ng Solution

Evaluate trigonometric functions in the problem

$$0.9009688679024191 + 0.6234898018587336 + 0.22252093395631445 + -0.22252093395631434 + -0.6234898018587335 + -0.900968867902419$$

Idagdag ang 0.9009688679024191 at 0.6234898018587336 para makuha ang 1.5244586697611527.

$$1.5244586697611527+0.22252093395631445-0.22252093395631434-0.6234898018587335-0.900968867902419$$

Idagdag ang 1.5244586697611527 at 0.22252093395631445 para makuha ang 1.74697960371746715.

$$1.74697960371746715-0.22252093395631434-0.6234898018587335-0.900968867902419$$

I-subtract ang 0.22252093395631434 mula sa 1.74697960371746715 para makuha ang 1.52445866976115281.

$$1.52445866976115281-0.6234898018587335-0.900968867902419$$

I-subtract ang 0.6234898018587335 mula sa 1.52445866976115281 para makuha ang 0.90096886790241931.

$$0.90096886790241931-0.900968867902419$$

I-subtract ang 0.900968867902419 mula sa 0.90096886790241931 para makuha ang 0.00000000000000031.

$$0.00000000000000031$$

I-factor

$$\frac{31}{2 ^ {17} \cdot 5 ^ {17}} = 3.1 \times 10^{-16}$$