Bonsoir ;
Exercice n ° 9 :
1) f(1) = -3 * 1² + 5 * 1 = -3 + 5 = 2 .
f(-3) = -3 * (-3)² + 5 * (-3) = -3 * 9 - 15 = -27 - 15 = - 42 .
f(10^3) = -3 * (10^3)² + 5 * 10^3 = -3 * 10^6 + 5 * 10^3
= -3 * 1 000 000 + 5 * 1 000 = -3 000 000 + 5 000
= - 2 995 000 .
2) f(6) = -3 * 6² + 5 * 6 = -3 * 36 + 30 = -108 + 30 = -78.
Exercice n ° 10 :
1) f(3) = -(3²) + 6/3 = -9 + 2 = -7 .
f(-4) = -(-4)² + 6/(-4) = -16 - 3/2 = (-32 - 3)/2 = - 35/2 = -17,5 .
2) f(2) = -(2²) + 6/2 = -4 + 3 = -1 .
f(1/2) = - (1/2)² + 6/(1/2) = -1/4 + 6 * 2 = -1/4 + 12 = -1/4 + 48/4
= 47/4 = 11,75 .