1. If F(x) = 2x + 8/x2,
calculate F(2) and F(-2)
2. If F(x) = -12/x2,
calculate F(2)
3. If P(x) = 2x3 + 3x2
-3x -2 evaluate P(1) and P(-2)
4. If P(x) = x3 –x2
+ 2x + 4 evaluate P(-1) and P(2)
5. If P(x) = ax3 + bx2
-3x -2 and P(1) = 0 and P(-2) = 0, find the values of a and b.
6. If P(x) = x3 –x2
+ ax + b and P(-1) = 0 and P(2) = 12, find the values of a and b.
f(2)= 2(2)+8/(2)^2=6
ReplyDeleteF(-2)= 2(-2)+8/(-2)^2=-2
f(2)= -12/(2)^2=-3
ReplyDelete3. P(1)= 2(1)^3+3(1)^2-3(1)-2= 0
P(2)= 2(-2)^3+3(-2)^2-3(1)-2= 0
4. P(1)= (-1)^3-(-1)^2+2(-1)+4=0
P(2)= (2)^3-(2)^2+2(2)+4=12
This comment has been removed by the author.
ReplyDeleteF(2) = 2(2)+ 8/(2)^2
ReplyDelete= 4+2
F(2) = 6
F(-2) = 2(-2) + 8/(-2)^2
= -4+2
F(-2) = -2
This comment has been removed by the author.
ReplyDelete1. 2x + 8/x^2
ReplyDelete8/x^2 ==> 8x^ -2
f(2)= 2(2) + 8(2)^ -2
= 4 + 0.25
= 4.25
f(-2)= 2(-2) + 8(-2)^ -2
= -4 - 0.25
= -4.25
2. -12/x^2 ==> -12x^ -2
f(2)= -12(2)^ -2
= -12(0.25)
= -3
3. P(x) = 2x^3 + 3x^2 -3x -2
P(1)= 2(1)^3 + 3(1)^2 - 3(1) - 2
= 0
P(-2)= 2(-2)^3 + 3(-2)^2 - 3(-2) - 2
= 0
4. P(x) = x^3 –x^2 + 2x + 4
P(-1)= (-1)^3 - (-1)^2 + 2(-1) + 4
= 0
P(2)= (2)^3 - (2)^2 + 2(2) + 4
= 12
5. P(x) = ax^3 + bx^2 -3x -2
P(1) = a(1)^3 + b(1)^2 -3(1) -2
0 = a + b - 3 -2
3+2 = a + b
5 = a +b <== eq 1
P(-2) = a(-2)^3 + b(-2)^2 -3(-2) -2
0 = -8a + 4b + 6 -2
-6 +2= -8a + 4b
-4 = -8a + 4b
-2 = -4a + 2b <== eq 2
From eq1 5-b=a
sub in eq 2 -2 = -4a + 2b
-2 = -4 (5-b) + 2b
-2 = -20 + 4b +2b
-2 +20= 6b
18 = 6b
3 = b
5= a +3
5 - 3 = a
2 = a ==> b=3 a=2
1) F(2) = 6
ReplyDeleteF(-2) = -2
2) F(2) = -3
3) P(1) = 0
P ( -2) = 32
4) P(-1) = 0
P (2) = 12
5) a = -2
b = 7
6) a = 3.3
b = 5.3
1)
ReplyDeletef(x)= 2[x] + 8/[x]^2
f(-2) = 2[-2] + 8/ [-2]^2
= -4 + 8/ [-4]
= -4 + 2
= -2
f(2)= 2[2] + 8/ [2]^2
= 4 + 8/4
= 4 + 2
= 6
2) f(x)= -12/x^2
ReplyDeleteF(2)
= -12/[2]^2
= -12/4
= -3
p(x)= 2[x]^3 + 3[x]^2 - 3[x] - 2
ReplyDeletep(-2)= 2[- 2]^3 + 3[-2]^2 - 3[-2] - 2
= - 16 - 12 + 6 -2
= 0
p(1)= 2[1]^3 + 3[1]^2 - 3[1] -2
=2 + 3 - 3 -2
= 0
4) p[x] = x^3 -x^2 + 2x + 4
ReplyDeletep(-1)=
[-1]^3 - [-1]^2 + 2[-1] + 4
= -1 -1 -2 +4
= 0
p[2]= [2]^3 - [2]^2 + 2[2] + 4
= 8 - 4 + 4 + 4
= 12
p[x]= ax^3 +bx^2- 3x-2
ReplyDeletep(1)=0
=a[1]^3 + b[1]^2 - 3[1] - 2
= a + b - 3 -2
=a + b - 5
= a + b = 5 ep 1
p[-2]= a[-2]^3 + b[-2]^2 -3[-2] - 2
=-8a + 4b + 6 - 2
=-8a + 4b + 4
= -8a + 4b = -4 eq 2
a + b = 5 in eq 1 make b the subjt
b= 5-a
-8a + 4b = -4 eq 2
-8a + 4(5-a) = -4 subs b into eq 2
-8a + 20 - 4a = -4
-12a + 20 = -4
a= -4-20/[-12]
=2
a+b=5 subs a into eq 1
(2) + b=5
b=5-2
=3
a= 2 b= 3
number 5
Deletep[x]= x^3 + x^2 + ax + b
ReplyDeletep[2]=12
[2]^3 - [2]^2+ a[2] + b = 12
8 - 4 + 2a + b = 12
4+ 2a + b =12
2a + b = 12-4
2a+b=8 eq1
p[-1]
[-1]^3 - [-1] ^2 + a[-1] +b
-1+1-a+b
a-b=-2 eq 2
2a + b = 8 eq 1
a-b= -2 eq 2
a=-2+b make a the subjt of eq 2
2a + b= 8 sub a into eq 1
2[-2+b]+b=8
-4+2b+b=8
3b=8+4
b=12/3
=4
a-b= -2 subs b into eq 2
a - 4= -2
a=-2+4
=2
a=2 b = 4
number 6.
Delete