Mathematics
Grade 11
15 min
Find trigonometric functions using a calculator
Find trigonometric functions using a calculator
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Correctly set a scientific calculator to either Degree or Radian mode based on the problem's requirements.
Accurately calculate the values of sine, cosine, and tangent for any given angle in both degrees and radians.
Evaluate the reciprocal trigonometric functions (cosecant, secant, cotangent) using the reciprocal identities and a calculator.
Use inverse trigonometric functions (sin⁻¹, cos⁻¹, tan⁻¹) to find the measure of an angle when given its trigonometric ratio.
Solve for angles in both degrees and radians using inverse trigonometric functions.
Evaluate complex expressions involving multiple trigonometric functions and arithmetic operations using a calculator.
How do engineers calculate the precise angle for a satellite dish to capture a signal f...
2
Key Concepts & Vocabulary
TermDefinitionExample
Degree Mode (DEG)A calculator setting for measuring angles where one full rotation is divided into 360 degrees (360°). This is the most common mode for introductory geometry and triangle problems.To find sin(45°), your calculator must be in Degree mode. The result is approximately 0.7071.
Radian Mode (RAD)A calculator setting for measuring angles based on the radius of a circle, where one full rotation is 2π radians. This mode is standard in calculus and higher-level physics.To find cos(π), your calculator must be in Radian mode. The result is -1.
Primary Trigonometric FunctionsThe three fundamental functions—sine (sin), cosine (cos), and tangent (tan)—which have dedicated keys on most scientific calculators.Pressing the [tan] key followed by 45 (in Degree mode) calc...
3
Core Formulas
Reciprocal Identities
csc(θ) = 1/sin(θ) \\ sec(θ) = 1/cos(θ) \\ cot(θ) = 1/tan(θ)
Use these formulas to find the value of a reciprocal function. First, calculate the corresponding primary function (sin, cos, or tan) of the angle, then find its reciprocal using the calculator's `1/x` or `x⁻¹` key.
Inverse Function Principle
If sin(θ) = x, then θ = sin⁻¹(x) \\ If cos(θ) = y, then θ = cos⁻¹(y) \\ If tan(θ) = z, then θ = tan⁻¹(z)
When you know the ratio (x, y, or z) and need to find the angle (θ), use the corresponding inverse function. The result will be an angle in degrees or radians, depending on the calculator's current mode.
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Sign Up Free to ContinueSample Practice Questions
Easy
To calculate the value of sin(2.5), where 2.5 is an angle in radians, what mode must your calculator be in?
A.Degree (DEG)
B.Radian (RAD)
C.Standard (STD)
D.Scientific (SCI)
Easy
Using a scientific calculator, what is the value of cos(180°) rounded to four decimal places?
A.1.0000
B.0.0000
C.-1.0000
D.Undefined
Easy
Which of the following is the correct calculator key sequence to find the value of cosecant of 70 degrees, csc(70°)?
A.[SHIFT] [sin] (70)
B.[1] [/] [cos] (70)
C.[1] [/] [sin] (70)
D.[csc] (70)
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