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3.1 Simplify (showing ALL calculations) the following WITHOUT using a calculator: 3.1.1 $\\sqrt{16 a^6}$ 3.1.2 $\\\sqrt{\\log_{32} + \log 100 + 9}$ 3.1.3 $(\\4\\sqrt{5} + \sqrt{2})(\\\sqrt{2 - 4\\sqrt{5}})$ 3.2 Solve for $x$: $\\log_{x} x = 3 - \log_{x} (x + 6)$ 3.3 Given the complex number $z = 2w - 7i$ where $w = \frac{1}{2} + 3i$ 3.3.1 Determine $z$ in the form $a + bi$ 3.3.2 Express $z$ in the polar form $z = r cis \theta$ (where $ heta$ is in degrees) 3.4 Solve for $a$ and $b$ if $a + b + (a + bi) - bi = 5 - 3i$ - NSC Technical Mathematics - Question 3 - 2021 - Paper 1

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3.1-Simplify-(showing-ALL-calculations)-the-following-WITHOUT-using-a-calculator:--3.1.1-$\\sqrt{16-a^6}$--3.1.2-$\\\sqrt{\\log_{32}-+-\log-100-+-9}$--3.1.3-$(\\4\\sqrt{5}-+-\sqrt{2})(\\\sqrt{2---4\\sqrt{5}})$--3.2-Solve-for-$x$:-$\\log_{x}-x-=-3---\log_{x}-(x-+-6)$--3.3-Given-the-complex-number-$z-=-2w---7i$-where-$w-=-\frac{1}{2}-+-3i$--3.3.1-Determine-$z$-in-the-form-$a-+-bi$--3.3.2-Express-$z$-in-the-polar-form-$z-=-r-cis-\theta$-(where-$-heta$-is-in-degrees)--3.4-Solve-for-$a$-and-$b$-if-$a-+-b-+-(a-+-bi)---bi-=-5---3i$-NSC Technical Mathematics-Question 3-2021-Paper 1.png

3.1 Simplify (showing ALL calculations) the following WITHOUT using a calculator: 3.1.1 $\\sqrt{16 a^6}$ 3.1.2 $\\\sqrt{\\log_{32} + \log 100 + 9}$ 3.1.3 $(\\4\\s... show full transcript

Worked Solution & Example Answer:3.1 Simplify (showing ALL calculations) the following WITHOUT using a calculator: 3.1.1 $\\sqrt{16 a^6}$ 3.1.2 $\\\sqrt{\\log_{32} + \log 100 + 9}$ 3.1.3 $(\\4\\sqrt{5} + \sqrt{2})(\\\sqrt{2 - 4\\sqrt{5}})$ 3.2 Solve for $x$: $\\log_{x} x = 3 - \log_{x} (x + 6)$ 3.3 Given the complex number $z = 2w - 7i$ where $w = \frac{1}{2} + 3i$ 3.3.1 Determine $z$ in the form $a + bi$ 3.3.2 Express $z$ in the polar form $z = r cis \theta$ (where $ heta$ is in degrees) 3.4 Solve for $a$ and $b$ if $a + b + (a + bi) - bi = 5 - 3i$ - NSC Technical Mathematics - Question 3 - 2021 - Paper 1

Step 1

3.1.1 $\\sqrt{16 a^6}$

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Answer

To simplify sqrt16a6\\sqrt{16 a^6}, we begin by applying the square root to each component:

16=4\\\sqrt{16} = 4

and

a6=a6/2=a3.\\\sqrt{a^6} = a^{6/2} = a^3.

Thus, the simplified form is:

4a3\boxed{4 a^3}

Step 2

3.1.2 $\\\sqrt{\\log_{32} + \log 100 + 9}$

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Answer

First, we use the property of logarithms:

log32=log1032log1010=52.\\log_{32} = \frac{\\log_{10} 32}{\\log_{10} 10} = \frac{5}{2}.

Next, we find:

log100=2.\\log 100 = 2.

Now combine:

log32+log100+9=52+2+9=52+42+182=272.\\\log_{32} + \log 100 + 9 = \frac{5}{2} + 2 + 9 = \frac{5}{2} + \frac{4}{2} + \frac{18}{2} = \frac{27}{2}.

Taking the square root, we find:

272=332.\\\sqrt{\\\frac{27}{2}} = \frac{3\\\sqrt{3}}{2}.

Thus, the final result is:

332\boxed{\\\frac{3\sqrt{3}}{2}}

Step 3

3.1.3 $(4\sqrt{5} + \sqrt{2})(\sqrt{2 - 4\sqrt{5}})$

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Answer

Start with the expression:

(45+2)(245).(4\sqrt{5} + \sqrt{2}) (\sqrt{2 - 4\sqrt{5}}).

Please note that:

24sqrt5\\2 - 4\\sqrt{5} is negative, so we can rewrite it using:

x2=x\\\sqrt{x^2} = |x|

due to the quadratic nature of the expression. Thus:

The product yields a complex expression that cannot be simplified further clearly without specific values for roots derived from actual numerical values. It simplifies logarithmically depending on conditions.

Thus:

(45+2)(245)\boxed{(4\sqrt{5} + \sqrt{2})(\sqrt{2 - 4\sqrt{5}})}

Step 4

3.2 Solve for $x$: $\\log_{x} x = 3 - \log_{x} (x + 6)$

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Answer

Using properties of logarithms:

We rewrite the equation as:

logxx+logx(x+6)=3.\\log_{x} x + \log_{x} (x + 6) = 3.

Then we know:

logx(x(x+6))=3\\log_{x} (x(x + 6)) = 3

Which converts to:

x(x+6)=x3=27.x(x + 6) = x^3 = 27.

So, the resultant cubic equation:

x2+6x27=0x^2 + 6x - 27 = 0

Applying the quadratic formula:

= \frac{-6 \pm 12}{2}$$ Thus: $$x = 3\text{ or } x = -9.$$ The valid solution is: $$\boxed{3}$$

Step 5

3.3.1 Determine $z$ in the form $a + bi$

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Answer

Given the relation:

z=2w7iz = 2w - 7i

and substituting for ww:

=2(12+3i)7i= 2(\frac{1}{2} + 3i) - 7i

Calculating gives:

=(1+6i)7i=1i.= (1 + 6i) - 7i = 1 - i.

Therefore, we have:

z=1iz = \boxed{1 - i}

Step 6

3.3.2 Express $z$ in the polar form $z = r cis \theta$ (where $ heta$ is in degrees)

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Answer

To convert to polar form, first calculate the modulus:

r=x2+y2=12+(1)2=2.r = \sqrt{x^2 + y^2} = \sqrt{1^2 + (-1)^2} = \sqrt{2}.

Next, compute the argument:

θ=tan1(yx)=tan1(11)=315.\theta = \tan^{-1}\left(\frac{y}{x}\right) = \tan^{-1}\left(\frac{-1}{1}\right) = 315^\circ.

Thus, in polar form:

z=2cis315.z = \sqrt{2} \text{cis} 315^\circ.

Hence, our final result is:

z=2cis315\boxed{z = \sqrt{2} \text{cis} 315^\circ}

Step 7

3.4 Solve for $a$ and $b$ if $a + b + (a + bi) - bi = 5 - 3i$

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Answer

Starting with:

a+b+(a+bi)bi=53ia + b + (a + bi) - bi = 5 - 3i

Combine like terms:

2a+b=52a + b = 5 and for i:0=3+b=3\text{and for } i: 0 = -3 + b = -3

This yields b=3.b = -3.

Now substitute back to find aa:

2a = 8 \\ a = 4.$$ Thus the values are: $$\boxed{a = 4, b = -3}$$

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