15) factor out cos: cos(x)(sin(x)+1)=0
Now this is true when either cos(x)=0 (x=pi/2 and 3pi/2)
Or when sin(x)=-1 (x=3pi/2)
So it's solutions are pi/2 and 3pi/2

7 0

3 years ago

A teacher wants to find out the average number of weekly reading hours of her students. She noted the number of reading hours of

Studentka2010 [4]

A-Either the mean or median; both are 8

7 0

4 years ago

5.b) If z^(1/2)=x^(1/2)+y^(1/2) , show that (x+y-z)^2=4xy

Rudik [331]

Answer:

Step-by-step explanation:

(x+y-z)²= 4xy
(x+y-z)²- 4xy = 0
(x+y-z)²-(2√x√y)² = 0
(x+y-z-2√x√y)(x+y-z+2√x√y) =0
[(√x-√y)²-z]*[(√x+√y)²-z]=0
(√x-√y)²-z = 0 or (√x+√y)²-z = 0

We have : z^(1/2)= x^(1/2)+y^(1/2) ⇒ √z = √x + √y ⇒ z = (√x + √y)²

so (√x+√y)²-z = 0

so (x+y-z)²= 4xy

3 0

3 years ago