Question

if alpha and beta are the zeroes of polynomial 2x²-4x+5 find the value of alpha²+beta²​

Answer 1

Answer:

 Alpha+ beta=-b/a

                        =2

alpha*beta=c/a

                 =5/2

so, alpha2 +beta2=

by using (a+b)2=a2+b2+2ab

(2)2=a2+b2+2(5/2)

4=a2+b2+5

a2+b2=-1

Answer 2

Answer:

$\alpha = - b \div a \: and \: \beta = c \div a$

so

$\alpha = 4 \div 2 = 2$

and

$\beta = 5 \div 2$

$\alpha {}^{2} = 2 {}^{2} = 4$

$\beta { }^{2} =( 5 \div 2) {}^{2} = 25 \div 4$

now 4+25/4=16/4+25/4=41/4

answer= 41/4