Answer:
Step-by-step explanation:
let x < 30 be the width of strip of lawn.
then (80-2x)(60-2x)=800
4800-160x-120x+4x²=800
4x²-280x+4000=0
x²-70 x+1000=0
x²-20x-50x+1000=0
x(x-20)-50(x-20)=0
(x-20)(x-50)=0
x=20,50
x=50(rejected)
x=20 m
Answer:
2
Step-by-step explanation:
1/5*10
Remember the basic trig identity
<u />
We can move the cosine term to the right side to get
We can then replace
in the original equation and basically factor the resulting equation like a quadratic:
Then, we can see that
either equals
or
. But since the range of cosine is only from
, cosine can't equal
at all! So, you just have to solve for x when
, which is when
(The last part of the solution says that k can be any integer.)
If you only want solutions in the range
, then your answer is just