Math Problem Statement

Find the exact value of x Adjacent: x Opposite: 20 cm Use cot (π/6) Hypotenuse: x Adjacent: 10 cm Use sec(π/6) Adjacent: 17 cm Opposite: x Use cot (60°) Hypotenuse: x Opposite: 11 cm Use cosec(45°)

Solution

Let's break down each part of the problem step by step:

1. Use of cot(π/6):

  • cot(θ) = adjacent / opposite
  • Given: adjacent = xx, opposite = 20 cm, and θ=π/6\theta = \pi/6 (or 60°).

We know that: cot(π/6)=adjacentopposite=x20\cot(\pi/6) = \frac{\text{adjacent}}{\text{opposite}} = \frac{x}{20}

From the standard trigonometric identity: cot(π/6)=1tan(π/6)=113=3\cot(\pi/6) = \frac{1}{\tan(\pi/6)} = \frac{1}{\frac{1}{\sqrt{3}}} = \sqrt{3}

Thus, we can write: x20=3\frac{x}{20} = \sqrt{3}

Now, solve for xx: x=203x = 20\sqrt{3}

2. Use of sec(π/6):

  • sec(θ) = hypotenuse / adjacent
  • Given: hypotenuse = xx, adjacent = 10 cm, and θ=π/6\theta = \pi/6.

We know that: sec(π/6)=hypotenuseadjacent=x10\sec(\pi/6) = \frac{\text{hypotenuse}}{\text{adjacent}} = \frac{x}{10}

From the standard trigonometric identity: sec(π/6)=1cos(π/6)=132=23\sec(\pi/6) = \frac{1}{\cos(\pi/6)} = \frac{1}{\frac{\sqrt{3}}{2}} = \frac{2}{\sqrt{3}}

Thus, we can write: x10=23\frac{x}{10} = \frac{2}{\sqrt{3}}

Now, solve for xx: x=23×10=203=2033x = \frac{2}{\sqrt{3}} \times 10 = \frac{20}{\sqrt{3}} = \frac{20\sqrt{3}}{3}

3. Use of cot(60°):

  • cot(θ) = adjacent / opposite
  • Given: adjacent = 17 cm, opposite = xx, and θ=60\theta = 60^\circ.

We know that: cot(60)=adjacentopposite=17x\cot(60^\circ) = \frac{\text{adjacent}}{\text{opposite}} = \frac{17}{x}

From the standard trigonometric identity: cot(60)=1tan(60)=13\cot(60^\circ) = \frac{1}{\tan(60^\circ)} = \frac{1}{\sqrt{3}}

Thus, we can write: 17x=13\frac{17}{x} = \frac{1}{\sqrt{3}}

Now, solve for xx: x=173x = 17\sqrt{3}

4. Use of cosec(45°):

  • cosec(θ) = hypotenuse / opposite
  • Given: hypotenuse = xx, opposite = 11 cm, and θ=45\theta = 45^\circ.

We know that: csc(45)=hypotenuseopposite=x11\csc(45^\circ) = \frac{\text{hypotenuse}}{\text{opposite}} = \frac{x}{11}

From the standard trigonometric identity: csc(45)=1sin(45)=122=2\csc(45^\circ) = \frac{1}{\sin(45^\circ)} = \frac{1}{\frac{\sqrt{2}}{2}} = \sqrt{2}

Thus, we can write: x11=2\frac{x}{11} = \sqrt{2}

Now, solve for xx: x=112x = 11\sqrt{2}


Summary of Solutions:

  1. x=203x = 20\sqrt{3} cm (from cot(π/6))
  2. x=2033x = \frac{20\sqrt{3}}{3} cm (from sec(π/6))
  3. x=173x = 17\sqrt{3} cm (from cot(60°))
  4. x=112x = 11\sqrt{2} cm (from cosec(45°))

Would you like more details on any of the steps or have any further questions?

Here are some related questions for deeper understanding:

  1. What is the relationship between trigonometric ratios and right-angled triangles?
  2. How can you derive the values of trigonometric functions for specific angles like 30°, 45°, and 60°?
  3. What is the difference between secant, cosecant, and cotangent functions?
  4. How do the values of trigonometric ratios change in different quadrants of the unit circle?
  5. How do you simplify expressions involving square roots in trigonometry?

Tip: When working with trigonometric identities, always remember the common values for sine, cosine, and tangent at key angles (like 30°, 45°, 60°) to help speed up calculations.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Trigonometric Ratios
Right-Angle Triangles

Formulas

cot(θ) = adjacent / opposite
sec(θ) = hypotenuse / adjacent
csc(θ) = hypotenuse / opposite

Theorems

Trigonometric Identities
Values of Trigonometric Ratios at Standard Angles

Suitable Grade Level

Grades 9-11