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- Hi, this is Rob.
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We're gonna solve radicals on the
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TI-84 Plus CE graphing calculator.
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Let's get started.
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First, press this mode button here.
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This screen pops up.
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I just wanna show you the current
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settings I have on my calculator.
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The items in black are
the current settings.
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You can change the settings by
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using the arrow keys and the enter button.
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Get out of the screen by
pressing the clear button.
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Okay, first radical is the
negative square root of 49.
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Press the negative sign here;
do not press the minus sign.
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Next press the 2nd key, next
press the x squared key.
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The square root symbol appears
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with a dotted box under the square root.
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Enter the 49.
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This right arrow symbol also appears.
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Press the right arrow key to
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exit out of the radical symbol.
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Now we're ready to solve this square root.
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Press the enter button and
there's the answer, negative 7.
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Press the clear button.
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This problem is the cube
root of a negative 512.
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To do cube roots, press the math key.
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This window pops up.
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Go down to number four and
press the enter button.
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This window pops up.
Enter a negative 512.
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Make sure to use the negative sign here,
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and not the minus sign.
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Click the right arrow button to get that
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blinking arrow under the
radical sign out of there.
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Now press the enter key
to solve this cube root.
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And there's the answer, negative 8.
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Press the clear button
for our next problem.
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In this problem, we take
the fifth root of 32.
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Press the math button,
this window appears.
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Go down to number five
and press the enter key.
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This window appears.
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Enter a five.
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Now press the right arrow key to move
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the cursor into the radical sign.
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Now enter a 32 and press
the right arrow key.
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Press the enter key to get the answer.
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And there is the answer, two.
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Okay, the next problem is the
square root of a negative 36.
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Press the 2nd button,
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then this x squared button,
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which is also the square root button.
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You know the drill: enter a negative 36
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and press the enter key.
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And we get an error message.
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Because this type of radical
involves imaginary numbers.
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Imaginary numbers is an
advanced topic in algebra.
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If you're going to work
with imaginary numbers,
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you need to change the mode
settings in the calculator.
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Press the clear button to
escape this error message.
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Press the mode key here,
this screen appears.
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Go down here and
highlight this a plus b i.
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Use the arrow keys to go
down and to the right.
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Highlight it in black and
then press the enter key.
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Now we're ready to go back to the problem.
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Press the clear key.
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You can see here that the mode has changed
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from real numbers to imaginary numbers.
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Re-enter the square root of negative 36.
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Now press the enter key
to solve the problem.
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And there is the answer, a six i.
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Okay, that is it.
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That is how to work with radicals
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on the TI-84 Plus CE graphing calculator.
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If you like this video,
please give it a thumbs up,
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and please subscribe to this channel.