Introduction to trigonometric ratios - PowerPoint PPT Presentation

About This Presentation
Title:

Introduction to trigonometric ratios

Description:

There are 3 basic ratios in trigonometry that can be used to find measures in right triangles ... Mnemonics can help you remember the trig ratios. SOHCAHTOA. or ... – PowerPoint PPT presentation

Number of Views:199
Avg rating:3.0/5.0
Slides: 18
Provided by: stud1096
Category:

less

Transcript and Presenter's Notes

Title: Introduction to trigonometric ratios


1
Introduction to trigonometric ratios
  • Trigonometry is the study of the relationship
    between sides and angles of triangles.
  • There are 3 basic ratios in trigonometry that can
    be used to find measures in right triangles

2
The 3 ratios are the sine of an angle, the cosine
of an angle, and the tangent of an angle
  • A trigonometric ratio is a ratio of 2 sides of a
    right triangle

3
Trigonometric ratios
  • In a right triangle, the sine of an angle is the
    ratio of the length of the leg opposite the angle
    to the length of the hypotenuse
  • Sin A Opposite
  • Hypotenuse

4
Trigonometric ratios
  • In a right triangle, the cosine of a triangle is
    the ratio of the leg adjacent to the angle to the
    length of the hypotenuse
  • Cos A Adjacent
  • Hypotenuse

5
Trigonometric ratios
  • In a right triangle, the tangent of an angle is
    the ratio of the leg opposite the angle to the
    length of the leg adjacent to the angle
  • Tan A opposite
  • adjacent

6
When used in equations, the sine, cosine, and
tangent are often abbreviated "sin", "cos", and
"tan"
7
Mnemonics can help you remember the trig ratios
  • SOHCAHTOA
  • or
  • Studying Our Homework Can Always Help To Obtain
    Achievement

8
Find the sin, cos, and tan of angle S
  • Sin a cos b tan a
  • c c b

S
b
c
U
T
a
9
Find sin, cos, and tan of angle G
3
4
10
Use a calculator to evaluate the sine, cosine and
tangent of an angle
  • Your calculator needs to be in DEGREE mode, not
    in radian mode

11
Use a calculator to evaluate each expression
  • Round to nearest hundredth
  • A) cos 72o
  • B) sin 30o
  • C) tan 70o
  • D) cos 30o
  • E) tan 45o
  • F) sin 25o

12
  • Trig ratios can be used to solve for unknown side
    lengths in right triangles.
  • An equation can be divided or multiplied by a
    trig ratio, just as it can with any real number

13
Solving for side lengths
  • Use Tangent ratio to find e to the nearest
    hundredth

13
72
e
14
Solving for side lengths
  • Use sin to find x to the nearest hundredth

x
8
32
15
T
5
U
12
V
  • Find sin ltT
  • Find tan ltU
  • Find cos ltT
  • Find sin ltU
  • Find cos ltU
  • Find tan ltT

16
Z
W
39
x
41
Y
  • Find x to the nearest tenth

17
Evaluate each expression
  • Sin 30o
  • Cos 90o
  • Tan 45o
Write a Comment
User Comments (0)
About PowerShow.com