I really need help answer has to fit in this box:

answer: idk

step-by-step explanation:

y = i/2 xtnop + (3i/2 tnop+ 1)

step-by-step explanation:

the picture is the step by step explanation.

the cross section of an object is the shape you get when you cut straight through an object.

thus the cross section of the human hair is a circle. hence the cross sectional area is the area of a circle and area of circle is :

a = 3.14 × r²

we are given that the average width of human hair is = 4 × (1 / 10³) cm.

so the diameter of the circle is = 4 × (1 / 10³) cm.

∴ radius r = (diameter/2) = 2 × (1/10³) cm

now area a = 3.14 × (2 × (1/10³))² cm²

scientific notation is a standard way of writing very large and very small numbers so that they’re easier to both compare and use in computations. to write in scientific notation, follow the form

n × 10 ᵃ

where n is a number between 1 and 10, but not 10 itself, and a is an integer (positive or negative number).

so area can be rewritten in scientific notation as :

⇒ 3.14 × 4 × (1/10⁶)

⇒ 12.56 × 10 ⁻⁶ cm²

⇒1.256 × 10⁻⁷ cm²

to prove that sin⁴a+2cos²a-cos⁴a, we can factor out cos²a

sin⁴a+2cos²a-cos⁴a

= sin⁴a+cos²a(2-cos²a)

since sin²a + cos²a = 1, cos²a = 1 - sin²a so substituting

= sin⁴a+cos²a(2-(1 - sin²a) )

= sin⁴a+cos²a(1 + sin²a)

= sin⁴a+cos²a+ sin²a cos²a distribution

= sin⁴a + sin²a cos²a +cos²a

= sin²a(sin²a+cos²a) +cos²a by factoring

= sin²a * 1 + cos²a by pythagorean identity

= 1 by pythagorean identity