Monday, October 06, 2008

MYP Algebra 2 - Error Analysis 1

Guided Practice p.411
#3 and 4
Explain the error made in simplifying the expression.
Posted by at

7 comments:

Anonymous said...

Adam

Error Analysis:

3. 3 x 5^(1/4) + 2 x 5^(1/4) = 5 x 10^1/4

-The error here is that the number under the radical for the answer should be 5, not 10, because 5^1/4 + 5^1/4 does not make 10^1/4. (5 x 2)^1/4 does.

4. (X/Y^8)^(1/3) = X^(1/3)/(Y^8)^(1/3) = X^(1/3)/Y^2

-The error here is that (Y^8)^(1/3) is not Y^2. The power of 8 is not square rooted here; instead, it should be Y^(8-3), which is Y^5. This is because the factors of Y to the power of 8 are Y, 8 times. (Y^3 x Y^5)^(1/3) is Y^5, because (Y^3)^(1/3) cancels.

6:02 PM
Bear said...

for #3 instead of addong what is under the radical, they should have added the 3 and 2 only not the 3 and 2 and the two 5's.

for #4 instead of having y^2, it should have been y^8/3 therefore x^(1/3) / y^(8/3)

6:24 PM
Anonymous said...

3. The error made in simplifying was that they added the numbers under the radicand, or the 5's. The two expressions had like radicals and all that needed to be done was add the coefficients. Instead the answer should have been 5(4th root of 5).

4. The error here was in the denominator in the final step. (y^8)1/3=y^8/3, not y^2.

9:27 PM
Anonymous said...

p. 411
3) The radicands (5) should not be added together. Since the root and radicand are the same( 4√5), the radical term is treated like a variable. 3x+2x=5x, just as 3* 4√5+ 2* 4√5 is equal to 3+2(4√5), or 5*4√5.

4) (y8)⅓ would simplify to (y)8/3, not (y)8/4. Therefore the denominator doesn't simplify to y2. It would be (y) 8/3, so the denominator would then have to be rationalized.

9:34 PM
Anonymous said...

3.You only add 3 and 2 because they are not like terms you dont add the radicands because they are like terms.

4. you multiply y^8* 1/3 to get y^8/3 and x^1/3 / y^8/3 as your final result, not x^1/3 / y^2 because y^2 is not 8 * 1/3.

2:58 AM
Anonymous said...

Error Analysis

3. 3 x 5^(1/4)+2 x 5^(1/4)=5 x 10^(1/4)

--The error in number 3 is that
3 x 5^(1/4)+2 x 5^(1/4) does not equal 5 x 10^(1/4) . This is because the two radicals were NOT treated as like radicals(like radicals have the same index and the same radicand). Meaning that 3 x 5^(1/4) and 2 x 5^(1/4) were suppose to be added together following the distrubitive property. Thus, the answer would have been 5 x 5^(1/4). The numbers under the radicands were not suppose to be added together.

4. (X/Y^8)^(1/3) = X^(1/3)/ (y^8)^(1/3)= X^(1/3) / Y^2

--The error in this problem is that y^8^(1/3) does not equal y^2.Because accoring to the power of quotient property the power of 8 and 1/3 were suppose to be multiplied together and when they are they result in the power of 8/3 rather than 2.

10:24 PM
Anonymous said...

holla@ ur boi!!!!!!!!!

2:18 PM

Post a Comment

Subscribe to: Post Comments (Atom)