Question

4x^2-5x-7=0 3x^2+2x=0 x^4-17x^2+16=0 найти дескрименант

Answer 1

4х² -5х -7 =0
D = b² -4ac = 25 -4·4·(-7) = 25 + 98 = 123
3х² -17х +16 = 0
D = b² - 4ac = 289 -4·3·16= 289 - 192=97
x^4 -17x^2 +16 = 0
x^2 = t
t^2 -17t +16 = 0
по т. Виета t1 = 1  и  b2 = 16
x^2 = 1              x^2 = 16
x = +-1               x= +-4