The quadratic x2-5x+6=2(x-4)2 has roots α and β. Find the exact value of αβ-α2 . Could you answer it step by step, thank you so much!
Problem: x2 - 5x + 6 = 2(x - 4)2 has answers A and B. Find the value of AB - A2
x2 - 5x + 6 = 2(x - 4)2
x2 - 5x + 6 = 2(x - 4)(x - 4)
x2 - 5x + 6 = 2(x2 - 8x + 16)
x2 - 5x + 6 = 2x2 - 16x + 32
Subtract x2 from both sides: - 5x + 6 = x2 - 16x + 32
Add 5x to both sides: 6 = x2 - 11x + 32
Subtract 6 frm both sides: 0 = x2 - 11x + 26
Use the quadratic equation with a = 1, b = -11, and c = 26:
A = [ -(-11) + sqrt( (11)2 - 4(1)(26) ) ] / [ 2(1) ] B = [ -(-11) - sqrt( (11)2 - 4(1)(26) ) ] / [ 2(1) ]
A = [11 + sqrt( 121 - 104 ) ] / [2] B = [11 + sqrt( 121 - 104 ) ] / [2]
A = [ 11 + sqrt( 17 ) ] / [ 2 ] B = [ 11 + sqrt( 17 ) ] / [ 2 ]
AB - A2 ---> [ 11 + sqrt( 17 ) ] / [ 2 ] · [ 11 + sqrt( 17 ) ] / [ 2 ] - { [ 11 + sqrt( 17 ) ] / [ 2 ] }2
---> [ 121 - 17 ] / 4 - [ 121 + 11sqrt(17) + 11sqrt(17) + 17 ] / 4
---> 104 / 4 - [ 138 + 22sqrt(17) ] / 4
---> [ - 34 - 22sqrt(17) ] 4
Problem: x2 - 5x + 6 = 2(x - 4)2 has answers A and B. Find the value of AB - A2
x2 - 5x + 6 = 2(x - 4)2
x2 - 5x + 6 = 2(x - 4)(x - 4)
x2 - 5x + 6 = 2(x2 - 8x + 16)
x2 - 5x + 6 = 2x2 - 16x + 32
Subtract x2 from both sides: - 5x + 6 = x2 - 16x + 32
Add 5x to both sides: 6 = x2 - 11x + 32
Subtract 6 frm both sides: 0 = x2 - 11x + 26
Use the quadratic equation with a = 1, b = -11, and c = 26:
A = [ -(-11) + sqrt( (11)2 - 4(1)(26) ) ] / [ 2(1) ] B = [ -(-11) - sqrt( (11)2 - 4(1)(26) ) ] / [ 2(1) ]
A = [11 + sqrt( 121 - 104 ) ] / [2] B = [11 + sqrt( 121 - 104 ) ] / [2]
A = [ 11 + sqrt( 17 ) ] / [ 2 ] B = [ 11 + sqrt( 17 ) ] / [ 2 ]
AB - A2 ---> [ 11 + sqrt( 17 ) ] / [ 2 ] · [ 11 + sqrt( 17 ) ] / [ 2 ] - { [ 11 + sqrt( 17 ) ] / [ 2 ] }2
---> [ 121 - 17 ] / 4 - [ 121 + 11sqrt(17) + 11sqrt(17) + 17 ] / 4
---> 104 / 4 - [ 138 + 22sqrt(17) ] / 4
---> [ - 34 - 22sqrt(17) ] 4