Question

If f(x) = X2 - (a+b)x +ab then find f(a),f(b) and f(a+b). (polynomial) ​

Answer 1

Answer:

f(a) = 0 ,f(b) = 0 ,f(a+b) = ab

Step-by-step explanation:

put x = a in

f(x) = x² - (a+b)x + ab

then

f(a) = a² - (a+b)a + ab

= a² - a² - ab + ab

= 0

now put x = b

then

f(b) = b² - (a+b)b + ab

= b² - ab - b² + ab

= 0

now put x = a+b

then

f(a+b) = (a+b)² - (a+b)(a+b) + ab

= (a+b)² - (a+b)² + ab

= ab