Answer:
cosx = sqrt(15)/4, -sqrt(15)/4
Step-by-step explanation:
cos²x = 1 - sin²sin x
cos²x = 1 - (1/4)²
cos²x = 15/16
cosx = sqrt(15)/4, -sqrt(15)/4
Answer:
Option D. AC= 10 cm and CE= 5 cm
Step-by-step explanation:
From the given figure two triangles ΔABC and ΔADE are similar and two lines BC║DE.
From these similar triangles we know


Therefore 
Or AC=
Now from pythagoras theorem
AE = √(AD²+ED²) = √(12²+9²) = √(144+81) =√225 = 15 cm
Since we know side AC = 
= 
= 10 cm
Therefore AC = 10 cm and AE = 15cm and CE = (15-10) = 5 cm
To get a decimal form of a fraction, divide the numerator by the denominator.
7/8 = 0.875