Photo AI

2. (a) Simplify $$\sqrt{32} + \sqrt{18}$$ giving your answer in the form $a\sqrt{2}$, where $a$ is an integer - Edexcel - A-Level Maths Pure - Question 4 - 2012 - Paper 1

Question icon

Question 4

2.-(a)-Simplify--$$\sqrt{32}-+-\sqrt{18}$$-giving-your-answer-in-the-form-$a\sqrt{2}$,-where-$a$-is-an-integer-Edexcel-A-Level Maths Pure-Question 4-2012-Paper 1.png

2. (a) Simplify $$\sqrt{32} + \sqrt{18}$$ giving your answer in the form $a\sqrt{2}$, where $a$ is an integer. (b) Simplify $$\frac{\sqrt{32} + \sqrt{18}}{3 + \sq... show full transcript

Worked Solution & Example Answer:2. (a) Simplify $$\sqrt{32} + \sqrt{18}$$ giving your answer in the form $a\sqrt{2}$, where $a$ is an integer - Edexcel - A-Level Maths Pure - Question 4 - 2012 - Paper 1

Step 1

Simplify $$\sqrt{32} + \sqrt{18}$$

96%

114 rated

Answer

To simplify 32\sqrt{32} and 18\sqrt{18}, we can break them down into their prime factors:

  1. Simplifying 32\sqrt{32}:
    32=16×2=16×2=42\sqrt{32} = \sqrt{16 \times 2} = \sqrt{16} \times \sqrt{2} = 4\sqrt{2}

  2. Simplifying 18\sqrt{18}:
    18=9×2=9×2=32\sqrt{18} = \sqrt{9 \times 2} = \sqrt{9} \times \sqrt{2} = 3\sqrt{2}

  3. Combine the results:
    32+18=42+32=(4+3)2=72\sqrt{32} + \sqrt{18} = 4\sqrt{2} + 3\sqrt{2} = (4 + 3)\sqrt{2} = 7\sqrt{2}

Thus, the final answer for part (a) is 727\sqrt{2}.

Step 2

Simplify $$\frac{\sqrt{32} + \sqrt{18}}{3 + \sqrt{2}}$$

99%

104 rated

Answer

To simplify the expression, first substitute the simplified forms from part (a):
32+18=72\sqrt{32} + \sqrt{18} = 7\sqrt{2}.

Thus, the expression becomes:

723+2\frac{7\sqrt{2}}{3 + \sqrt{2}}.

Next, we rationalize the denominator:

  1. Multiply numerator and denominator by the conjugate:
    72(32)(3+2)(32)\frac{7\sqrt{2}(3 - \sqrt{2})}{(3 + \sqrt{2})(3 - \sqrt{2})}.

  2. Calculate the denominator:
    (3+2)(32)=32(2)2=92=7.(3 + \sqrt{2})(3 - \sqrt{2}) = 3^2 - (\sqrt{2})^2 = 9 - 2 = 7.

  3. Calculate the numerator:
    72(32)=2127(2)=21214.7\sqrt{2}(3 - \sqrt{2}) = 21\sqrt{2} - 7(2) = 21\sqrt{2} - 14.

Now we have:

212147\frac{21\sqrt{2} - 14}{7}.

  1. Simplify:
    2127147=322.\frac{21\sqrt{2}}{7} - \frac{14}{7} = 3\sqrt{2} - 2.

Thus, the final answer for part (b) is 3223\sqrt{2} - 2.

Join the A-Level students using SimpleStudy...

97% of Students

Report Improved Results

98% of Students

Recommend to friends

100,000+

Students Supported

1 Million+

Questions answered

;