< Return to Video

Radical Equivalent to Rational Exponents 2

  • 0:01 - 0:02
    Rewrite the radical expression
  • 0:02 - 0:06
    using rational exponents and simplify.
  • 0:06 - 0:10
    So here we have the fourth root of 5 a to the fourth
  • 0:10 - 0:12
    b to the twelfth power.
  • 0:12 - 0:16
    The key thing to realize here is the fourth root of something
  • 0:16 - 0:20
    is same thing as something to the one fourth power.
  • 0:20 - 0:23
    Or in particular, or in general, the nth root something
  • 0:23 - 0:28
    is the same thing as that something to the 1 over n power.
  • 0:28 - 0:30
    So we can just apply that over here:
  • 0:30 - 0:31
    the fourth root of all of this
  • 0:31 - 0:35
    is equal to 5 a to the 4th, b to the 12th power,
  • 0:35 - 0:38
    all of that to the one fourth power.
  • 0:38 - 0:41
    And then we also know if we take the product of things,
  • 0:41 - 0:43
    and then raise them to some exponent,
  • 0:43 - 0:47
    that's the same thing as raising each of the terms in the product
  • 0:47 - 0:48
    to the exponent first,
  • 0:48 - 0:51
    or each of the things that we're taking the product of
  • 0:51 - 0:53
    to that exponent, and then multiplying.
  • 0:53 - 0:55
    So let's do that.
  • 0:55 - 0:57
    So 5, so this is the same thing as
  • 0:57 - 0:59
    5 to the 1/4 power
  • 0:59 - 1:02
    times a to the fourth to the 1/4 power
  • 1:02 - 1:07
    times b to the 12th to the 1/4 power.
  • 1:07 - 1:10
    Now 5 to the 1/4,
  • 1:10 - 1:11
    I don't know what that is,
  • 1:11 - 1:14
    so I'll just keep that as the cube root,
  • 1:14 - 1:16
    well, we could leave it as 5 to the 1/4,
  • 1:16 - 1:18
    and that's not not simplified.
  • 1:18 - 1:23
    or we can just rewrite it again as the fourth root of 5.
  • 1:23 - 1:25
    a to the fourth to the 1/4 power:
  • 1:25 - 1:29
    if your raise something to a power and then another power,
  • 1:29 - 1:30
    and raise that to another power,
  • 1:30 - 1:35
    that's equivalent of raising a to the four times 1/4 power.
  • 1:35 - 1:36
    So let me just write that down.
  • 1:36 - 1:41
    This is, so times a to four times 1/4 power.
  • 1:41 - 1:44
    And then finally, this right over here,
  • 1:44 - 1:47
    using the same exact exponent property,
  • 1:47 - 1:51
    this is b to the 12th times 1/4 power.
  • 1:51 - 1:53
    So all of this simplifies to,
  • 1:53 - 1:55
    and I'll change the order here,
  • 1:55 - 1:59
    so you have the fourth root of 5,
  • 1:59 - 2:03
    and then you have a to the fourth times 1/4 power
  • 2:03 - 2:05
    so that's just, this simplifies to a to the first power
  • 2:05 - 2:07
    which is really just the same thing as a.
  • 2:07 - 2:09
    So that's just a.
  • 2:09 - 2:14
    And then we have b to the 12 times 1/4 power.
  • 2:14 - 2:16
    Well, 12 times 1/4 is just three.
  • 2:16 - 2:19
    So that's b to the third power.
  • 2:19 -
    So it's a, b to the third power times the fourth root of 5.
Title:
Radical Equivalent to Rational Exponents 2
Description:

u16_l1_t3_we2 Radical Equivalent to Rational Exponents 2

more » « less
Video Language:
English
Duration:
02:24
Christi Rockwell edited English subtitles for Radical Equivalent to Rational Exponents 2
Hillarygf added a translation

English subtitles

Revisions