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Find the value of : (5sin^(3)30^(@)+co...

Find the value of :
`(5sin^(3)30^(@)+cos^(2)45^(@)-4tan^(2)30^(@))/(2sin 30^(@).cos30^(@)+tan45^(@))+cos 0^(@)`

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To solve the expression \[ \frac{5\sin^3(30^\circ) + \cos^2(45^\circ) - 4\tan^2(30^\circ)}{2\sin(30^\circ)\cos(30^\circ) + \tan(45^\circ)} + \cos(0^\circ), \] we will evaluate each trigonometric function step by step. ### Step 1: Calculate the trigonometric values 1. **Calculate \(\sin(30^\circ)\)**: \[ \sin(30^\circ) = \frac{1}{2} \] 2. **Calculate \(\cos(45^\circ)\)**: \[ \cos(45^\circ) = \frac{\sqrt{2}}{2} \] 3. **Calculate \(\tan(30^\circ)\)**: \[ \tan(30^\circ) = \frac{1}{\sqrt{3}} \] 4. **Calculate \(\tan(45^\circ)\)**: \[ \tan(45^\circ) = 1 \] 5. **Calculate \(\cos(0^\circ)\)**: \[ \cos(0^\circ) = 1 \] ### Step 2: Substitute the values into the expression Now substitute these values into the expression: 1. **Calculate \(\sin^3(30^\circ)\)**: \[ \sin^3(30^\circ) = \left(\frac{1}{2}\right)^3 = \frac{1}{8} \] 2. **Calculate \(\cos^2(45^\circ)\)**: \[ \cos^2(45^\circ) = \left(\frac{\sqrt{2}}{2}\right)^2 = \frac{2}{4} = \frac{1}{2} \] 3. **Calculate \(\tan^2(30^\circ)\)**: \[ \tan^2(30^\circ) = \left(\frac{1}{\sqrt{3}}\right)^2 = \frac{1}{3} \] ### Step 3: Substitute into the numerator Now substitute these values into the numerator: \[ 5\sin^3(30^\circ) + \cos^2(45^\circ) - 4\tan^2(30^\circ) = 5\left(\frac{1}{8}\right) + \frac{1}{2} - 4\left(\frac{1}{3}\right) \] Calculating each term: 1. \(5\left(\frac{1}{8}\right) = \frac{5}{8}\) 2. \(\frac{1}{2} = \frac{4}{8}\) 3. \(4\left(\frac{1}{3}\right) = \frac{4}{3}\) Now, find a common denominator to combine these fractions. The least common multiple of 8 and 3 is 24. Convert each term: 1. \(\frac{5}{8} = \frac{15}{24}\) 2. \(\frac{4}{8} = \frac{12}{24}\) 3. \(\frac{4}{3} = \frac{32}{24}\) Now substitute back into the numerator: \[ \frac{15}{24} + \frac{12}{24} - \frac{32}{24} = \frac{15 + 12 - 32}{24} = \frac{-5}{24} \] ### Step 4: Substitute into the denominator Now calculate the denominator: \[ 2\sin(30^\circ)\cos(30^\circ) + \tan(45^\circ) = 2\left(\frac{1}{2}\right)\left(\frac{\sqrt{3}}{2}\right) + 1 \] Calculating: 1. \(2\left(\frac{1}{2}\right)\left(\frac{\sqrt{3}}{2}\right) = \frac{\sqrt{3}}{2}\) 2. \(1 = \frac{2}{2}\) Now combine: \[ \frac{\sqrt{3}}{2} + \frac{2}{2} = \frac{\sqrt{3} + 2}{2} \] ### Step 5: Combine the entire expression Now substitute the numerator and denominator back into the expression: \[ \frac{\frac{-5}{24}}{\frac{\sqrt{3} + 2}{2}} + 1 \] This simplifies to: \[ \frac{-5}{24} \cdot \frac{2}{\sqrt{3} + 2} + 1 = \frac{-10}{24(\sqrt{3} + 2)} + 1 \] ### Step 6: Simplify the expression Now simplify: \[ \frac{-10}{24(\sqrt{3} + 2)} + 1 = 1 - \frac{10}{24(\sqrt{3} + 2)} \] To combine these, find a common denominator: \[ \frac{24(\sqrt{3} + 2)}{24(\sqrt{3} + 2)} - \frac{10}{24(\sqrt{3} + 2)} = \frac{24(\sqrt{3} + 2) - 10}{24(\sqrt{3} + 2)} \] This simplifies to: \[ \frac{24\sqrt{3} + 48 - 10}{24(\sqrt{3} + 2)} = \frac{24\sqrt{3} + 38}{24(\sqrt{3} + 2)} \] ### Final Answer Thus, the final value of the expression is: \[ \frac{24\sqrt{3} + 38}{24(\sqrt{3} + 2)} \]
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EDUCART PUBLICATION-SAMPLE PAPER 7-PART - B (SECTION - IV)
  1. Solve for x and y : x+(y)/(4)=11," "(5x)/(6)-(y)/(3)=7

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  2. A 2-digit number is such that the product of the digit is 20. If 9 is ...

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  3. triangle ABC with vertices A(0-2,0),B(2,0) and C(0,2) is similar to tr...

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  4. Prove that the lengths of tangents drawn from an external point to a c...

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  5. In the figure, PQ and RS are the common tangents to two circles inters...

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  6. Two concentric circles with radius 3 cm and 9.25 cm. Find the length o...

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  7. A number x is selected from the numbers 1,2,3 and then a second number...

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  8. Find the value of : (5sin^(3)30^(@)+cos^(2)45^(@)-4tan^(2)30^(@))/(2...

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  9. The first and the last terms of an A.P. are 17 and 350 respectively. I...

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  10. Prove that 2sqrt3-4 is an irrational number, using the fact that sqrt3...

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  11. The sum of two numbers, as well as, the difference of their squares is...

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  12. Find the values of k for which the following equations have an infinit...

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  13. triangle ABC with vertices A(0-2,0),B(2,0) and C(0,2) is similar to tr...

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  14. Prove that the sum of the squares of the sides of a rhombus is equa...

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  15. From a point P, two tangents PT and PS are drawn to a circle with cent...

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  16. A cylindrical bucket, 32 cm high and with radius of base 18 cm, is ...

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  17. Find the area of the shaded region (use pi = (22)/(7))

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  18. Find out area of triangle OAB and BCD shown in figure :-

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