evalute the following x^2 - x-2 at x=1,2,3
Answers
Step-by-step explanation:
ANSWER
x
2
(3−2x+x
2
)
For x=1;x=−1;x=2/3 and x=−1/2
x
2
(3−2x+x
2
)=3x
2
−2x
3
+x
4
(a) For x=1
3x
2
−2x
3
+x
4
=3(1)
2
−2(1)
3
+(1)
4
= 3×1−2×1+1
= 3−2+1=2
(b) For x=−1
3x
2
−2x
3
+x
4
=3(4)
2
−2(4)
3
+(−1)
4
= 3×1−2×(−1)+1
= 3+2+1=6
(c) For x=2/3
3x
2
−2x
3
+x
4
=3(2/3)
2
−2(2/3)
3
+(2/3)
4
= 3×(4/9)−2×(8/27)+(16/81)
= (4/3)−(16/27)+(16/81)
= (108−48+16)/81
= (124−48)/81
= 76/81
(d) For x=−1/2
3x
2
−2x
3
+x
4
=3(−1/2)
2
−2(4/2)
3
+(−1/2)
4
= 3×(1/4)−2×(−1/8)+(1/16)
= (3/4)+1/4+(1/16)
= (12+4+1)/16
= 17/16