Bagaimana anda mencari nol, jika ada, y = -7x ^ 2-x + 22 menggunakan formula kuadratik?

Jawapan:

#x = - (1 + sqrt (617)) / 14or- (1-sqrt (617)) / 14 #

# x = -1.846 atau 1.702 #

Penjelasan:

Diberikan # ax ^ 2 + bx + c #, nol diberikan oleh:

#x = (- b + -sqrt (b ^ 2-4ac)) / (2a) #

# a = -7 #

# b = -1 #

# c = 22 #

# x = (1 + -sqrt ((- 1) ^ 2-4 (-7) (22))) / (2 (-7)) #

# x = (1 + -sqrt (1 + 616)) / - 14 #

#x = - (1 + -sqrt (617)) / 14 #

#x = - (1 + sqrt (617)) / 14or- (1-sqrt (617)) / 14 #

# x = -1.846 atau 1.702 #