Math Problem Statement

Diketahui segitiga ABC dengan siku-siku di B dan sudut C adalah α. Tentukan perbandingan trigonometri (sin, cos, tan) dari segitiga tersebut.

Solution

The question in the image involves a right triangle ABC\triangle ABC where angle CC is given as α\alpha, and side lengths AB=6AB = 6 and BC=4BC = 4 are specified. You are asked to determine the trigonometric ratios: sinα\sin \alpha, cosα\cos \alpha, and tanα\tan \alpha.

Solution:

Step 1: Calculate the hypotenuse

Using the Pythagorean theorem to find the length of the hypotenuse ACAC: AC=AB2+BC2=62+42=36+16=52=213AC = \sqrt{AB^2 + BC^2} = \sqrt{6^2 + 4^2} = \sqrt{36 + 16} = \sqrt{52} = 2\sqrt{13}

Step 2: Determine trigonometric ratios

Since α\alpha is at angle CC, the sides relative to angle α\alpha are:

  • Opposite side: AB=6AB = 6
  • Adjacent side: BC=4BC = 4
  • Hypotenuse: AC=213AC = 2\sqrt{13}

Now, the trigonometric ratios are:

  • sinα=oppositehypotenuse=6213=313\sin \alpha = \frac{\text{opposite}}{\text{hypotenuse}} = \frac{6}{2\sqrt{13}} = \frac{3}{\sqrt{13}}
  • cosα=adjacenthypotenuse=4213=213\cos \alpha = \frac{\text{adjacent}}{\text{hypotenuse}} = \frac{4}{2\sqrt{13}} = \frac{2}{\sqrt{13}}
  • tanα=oppositeadjacent=64=1.5\tan \alpha = \frac{\text{opposite}}{\text{adjacent}} = \frac{6}{4} = 1.5

If you wish to rationalize the results: sinα=313×1313=31313\sin \alpha = \frac{3}{\sqrt{13}} \times \frac{\sqrt{13}}{\sqrt{13}} = \frac{3\sqrt{13}}{13} cosα=213×1313=21313\cos \alpha = \frac{2}{\sqrt{13}} \times \frac{\sqrt{13}}{\sqrt{13}} = \frac{2\sqrt{13}}{13}

Thus:

  • sinα=31313\sin \alpha = \frac{3\sqrt{13}}{13}
  • cosα=21313\cos \alpha = \frac{2\sqrt{13}}{13}
  • tanα=1.5\tan \alpha = 1.5

Would you like more details or further explanation?

Here are some related questions you can explore:

  1. How do you calculate the hypotenuse in any right triangle?
  2. What are the definitions of the basic trigonometric functions in a right triangle?
  3. How can you rationalize a denominator when working with trigonometric functions?
  4. What are the identities relating sin\sin, cos\cos, and tan\tan?
  5. How do you find the angle α\alpha if you know sinα\sin \alpha?

Tip: Always check whether your triangle's side lengths match the conditions of a right triangle using the Pythagorean theorem.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Right Triangle
Pythagorean Theorem

Formulas

sin(α) = opposite / hypotenuse
cos(α) = adjacent / hypotenuse
tan(α) = opposite / adjacent
Pythagorean theorem: a^2 + b^2 = c^2

Theorems

Pythagorean Theorem

Suitable Grade Level

Grade 10-11