2019-수학-가형-홀수-11¶
문제¶
풀이¶
from sympy import *
t, x = symbols('t x')
eqn = 6*x**2+(4*cos(t))*x+sin(t)
solve(eqn,x)
[-sqrt(-6*sin(t) + 2*cos(2*t) + 2)/6 - cos(t)/3,
sqrt(-6*sin(t) + 2*cos(2*t) + 2)/6 - cos(t)/3]
sol = solveset(discriminant(eqn)<0, t, domain = Interval.open(0, 2*pi))
sol
\[\displaystyle \left(\frac{\pi}{6}, \frac{5 \pi}{6}\right)\]
alpha = pi/6
beta = 5*pi/6
3*alpha+beta
\[\displaystyle \frac{4 \pi}{3}\]