Answer:
√2(√3 - 1)/4
Step-by-step explanation:
To find an exact value for Cos75°, we use the compound angle formula. Since 75° = 45° + 30°, Cos75° = Cos(45° + 30°).
Using Cos(A + B) = CosACosB - SinASinB where A = 45° and B = 30°,
Cos75° = Cos(45° + 30°) = Cos45°Cos30° - Sin45°Sin30°
Now Cos45° = Sin45° = 1/√2 = √2/2, Cos30° = √3/2 and Sin30° = 1/2.
Substituting these values into the above equation, we have
Cos75° = Cos(45° + 30°)
= Cos45°Cos30° - Sin45°Sin30°
= √2/2 × √3/2 - √2/2 × 1/2
= √6/4 -√2/4
= √2(√3 - 1)/4
Triangle: 13.3 km Why: the formula is 1/2 base x height.
Square: 57.4 Why: 7x8.2 which equals 57.4
Givens
Let the number of students in the class be x
Let the number of pieces of gum she gave out be 3x
Equation
3x + 8 = 168 This will not work out evenly. Let's try x - 1. The reason for that is because she may not give out anything to herself.
3(x - 1) + 8 = 168 This doesn't work either.
Well we have to choose. It's a rounding problem.
3x + 8 = 168 Subtract 8 from both sides.
3x = 168 - 8 Combine
3x = 160 Divide by 3 on both sides.
x = 160 / 3
x = 53.333333333
Since that can't be, we could say there were 53 students.
3x
Use distance formula.
√(2-5)²+(2-4)²
√(-3)²+(-2)²
√9+4
√13
Letter D.
Ok, the perimeter of the rectangle is 40 inches.
