Verified answer

y = ax² + bx + c

x(верш) = -b/2a

y(верш) = - D/4a = - (b² - 4ac)/4a (или подставить значения x)

y = x² - 18x + 45

x(верш) = -b/2a = - (-18)/2 = 9

y(верш) = 9² - 18*9 + 45 = 81 - 162 + 45 = -36

ответ (9, -36)

Verified answer