Use TrianCal to draw a triangle with phi as Great Piramid (minimum perimeter given 2 equal heights) = maximun stability.

NOTE: Phi=(1+√5)/2≈1.62 and acos(1/Phi)≈51.83º

8 0

3 years ago

Find x, if 3x − 5(y + x ) ^2 = 16 and 4x + 2(y + x )^ 2 = 30

lana66690 [7]

Answer:

x = 7

Step-by-step explanation:

Start by solving for $(y+x)^2$ which is a common expression for both equations. Then in the first equation:

$3\,x5\,(y+x)^2=16\\3x-16=5\,(y+x)^2\\(y+x)^2=\frac{3\,x-16}{5}$

and in the second equation:

$4\,x+2\,(y+x)^2=30\\2\,(y+x)^2=30-4\,x\\(y+x)^2=15-2\,x$

Now we make the two $(y+x)^2$ expressions equal so we get:

$\frac{3\,x-16}{5} =15-2\,x\\3\,x-16=75-10\,x\\13\,x=75+16\\13\,x=91\\x=7$

8 0

3 years ago

I need help with the circled ones

Fantom [35]

For number 7 what is the formula for volume of a cube

6 0

3 years ago