Question

x^2 - 3x + 4 =0

The formula is -b (+,-) square root of b^2 - 4ac/2(a)(c)

a = 1
b = -3x
c = 4

The answer I got is 3/8 + square root of 7/8, and 3/8 - square root of 7/8

Is this right?

Answer 1

substitute and check

Answer 2

if you just want to check your answers you can use wolfram: http://www2.wolframalpha.com/input/?i=x%5E2-3x%2B4

Answer 3

what's everybody doing in this thread ?

Answer 4

I came here to be nosey

Answer 5

b=-3 not -3x

Answer 6

X^2-3x+4
(X+1(X-4)
X= -1
X= 4

Answer 7

I know that you do that always

Answer 8

pardon but this formula from exersice is wrong there is 4ac/2a hence is correct

Answer 9

-4ac/2a

Answer 10

the formula according to my math books is -b (+,-) b^2-4(a)(c)) /2 (a)

Answer 11

so x_1,_2=(-b+/- sqrt(b2 -4ac))/2a

Answer 12

yes 2a but if you check when you have wrote this exercise firstly there is /2ac

Answer 13

Whoops, I just noticed that right now.

Answer 14

yes and b= -3 not -3x

Answer 15

so I just re did this, and would it be 3/2+ squareroot 7/2, and 3/2 - square root 7/2?

Answer 16

not is right because there is sqrt(9-16)/2 = sqrt(-7)/2what will be (3+/-isqrt7)/2

Answer 17

ok ?

Answer 18

Ok, I'm still a little confused. What I have is 3 square root 9-16. Which would 3+7 over 2 (square root sign over the 7)

Answer 19

It would really help if I could write out the answer with the actual square root and fractions. I don't know if tha'ts possible here

Answer 20

no will be isqrt7 becauqse inside radical will be minus 7

Answer 21

and we know that i squared is -1