Question

Tolong dibantu dong semuanya, ini caranya gimana ya?
tentukan hp dari:
y=2x+4
y=x^2+4x

Answer 1

y1 = 2x + 4
y2 = x² + 4x
y2 = y1
x² + 4x = 2x + 4
x² + 2x - 4 = 0
D = b² - 4ac
= (2)² - 4(1)(-4)
= 4 + 16
= 20 ---> √D = √20 = 2√5

x1 , x2 = [ -b ± √D ] / 2a
= [ -(2) ± 2√5 ] / 2(1)
= [ -2 ± 2√5 ] / 2
= -1 ± √5

x1 = -1 - √5
x2 = -1 + √5
HP = { ( -1 - √5 ) , ( √5 - 1 ) }

Answer 2

Dik :  y1 = 2x + 4
        y2 = x^2 + 4x
        y2 = y1
x^2 + 4x = 2x + 4 
x^2 + 2x - 4 = 0 

mis : E = b^2 - 4ac
         E = (2)^2. 4(1)(-4)
         E = 4 + 16 = 20 =2√5
digabung :
= { -2 (+/-) 2√5 } : 2 ------- { -2 (+/-) 2√5 :2 = -1 (+/-) √5


hp ( x2 dan x1 = -1 (+/-)√5 dan √5 -1