By definition of tangent,
tan(<em>x</em>) = sin(<em>x</em>) / cos(<em>x</em>)
so if tan(<em>x</em>) < 0, and we're given cos(<em>x</em>) = -1/4 < 0, then it follows that sin(<em>x</em>) > 0.
Recall the Pythagorean identity:
cos²(<em>x</em>) + sin²(<em>x</em>) = 1 → sin(<em>x</em>) = + √(1 - cos²(<em>x</em>))
Then
sin(<em>x</em>) = √(1 - (-1/4)²) = √(15/16) = √(15)/4
Recall the double angle identity:
sin(2<em>x</em>) = 2 sin(<em>x</em>) cos(<em>x</em>)
Then
sin(2<em>x</em>) = 2 • √(15)/4 • (-1/4) = -2√(15)/16 = -√(15)/8
It's 35 because 10 plus 5 is 15. You the subtract it by 50 and you get 35.
David spends 100 minutes exercising everyday. We can make a proportion here, and it is very easy. 40%/100% = 40 minutes/ x minutes. Because the two sides have the sane numerator, they must also have the same denominator to be equal.
Answer:
0.476190476 = decimal
10/21 = fraction
(hope this helps) (brainliest please)
Step-by-step explanation:
3 feet 8 inches converted to inches is 3x12+8=44inches
44inches times 4 pieces is 176 inches.
176 inches converted back to feet and inches is 176/12=14 feet 8 inches so he would need 15 feet of board
