Answer:
The second one (3x, 9x)
Step-by-step explanation:
Like terms are the terms that either have the same variable or have no variable.
Answer:
sin²x = (1 - cos2x)/2 ⇒ proved down
Step-by-step explanation:
∵ sin²x = (sinx)(sinx) ⇒ add and subtract (cosx)(cosx)
(sinx)(sinx) + (cosx)(cosx) - (cosx)(cosx)
∵ (cosx)(cosx) - (sinx)(sinx) = cos(x + x) = cos2x
∴ - cos2x + cos²x = -cos2x + (1 - sin²x)
∴ 1 - cos2x - sin²x = (1 - cos2x)/2 ⇒ equality of the two sides
∴ (1 - cos2x) - 1/2(1 - cos2x) = sin²x
∴ 1/2(1 - cos2x) = sin²x
∴ sin²x = (1 - cos2x)/2
Answer:
A) 3 in
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
<u>Geometry</u>
- Surface Area of a Sphere: SA = 4πr²
- Diameter: d = 2r
Step-by-step explanation:
<u>Step 1: Define</u>
SA = 23 in²
<u>Step 2: Find </u><em><u>r</u></em>
- Substitute [SAS]: 23 in² = 4πr²
- Isolate <em>r </em>term: 23 in²/(4π) = r²
- Isolate <em>r</em>: √[23 in²/(4π)] = r
- Rewrite: r = √[23 in²/(4π)]
- Evaluate: r = 1.35288 in
<u>Step 3: Find </u><em><u>d</u></em>
- Substitute [D]: d = 2(1.35288 in)
- Multiply: d = 2.70576 in
- Round: d ≈ 3 in
