Рациональное - без корня.
![\sqrt{25000} = \sqrt{2500 \times 10} = 50 \sqrt{10} \\ \sqrt{0.4} = \sqrt{10 \times 0.04} = 0.2 \sqrt{10} \\ \sqrt{25 \frac{4}{9} } = \sqrt{ \frac{229}{9} } = \frac{ \sqrt{229} }{3}](https://tex.z-dn.net/?f=+%5Csqrt%7B25000%7D++%3D++%5Csqrt%7B2500+%5Ctimes+10%7D++%3D+50+%5Csqrt%7B10%7D++%5C%5C++%5Csqrt%7B0.4%7D++%3D++%5Csqrt%7B10+%5Ctimes+0.04%7D++%3D+0.2+%5Csqrt%7B10%7D++%5C%5C++%5Csqrt%7B25+%5Cfrac%7B4%7D%7B9%7D+%7D++%3D++%5Csqrt%7B+%5Cfrac%7B229%7D%7B9%7D+%7D++%3D++%5Cfrac%7B+%5Csqrt%7B229%7D+%7D%7B3%7D+)
Ответ: нету верного ответа.
17*cos2α=17*(1-2*sin²α)=17-34sin²α
sinα=0,8
17cos2α=17-34*(0,8)²=17-21,76=-4,76
<span> y=kx+b
A(0;15)
</span> 15=k*0+b
b = 15
<span>
B(5/3;0)
</span> 0=k*5/3+15
0=k*5+15*3
k*5= - 15*3
k = - 9
Ответ: k = - 9; b = 15; y=-9x+15