Answer:
D. Pythagorean
Step-by-step explanation:
Given the identity
cos²x - sin²x = 2 cos²x - 1.
To show that the identity is true, we need to show that the left hand side is equal to right hand side or vice versa.
Starting from the left hand side
cos²x - sin²x ... 1
According to Pythagoras theorem, we know that x²+y² = r² in a right angled triangle. Coverting this to polar form, we have:
x = rcostheta
y = rsintheta
Substituting into the Pythagoras firnuka we have
(rcostheta)²+(rsintheta)² = r²
r²cos²theta+r²sin²theta = r²
r²(cos²theta+sin²theta) = r²
(cos²theta+sin²theta) = 1
sin²theta = 1 - cos²theta
sin²x = 1-cos²x ... 2
Substituting equation 2 into 1 we have;
= cos²x-(1-cos²x)
= cos²x-1+cos²x
= 2cos²x-1 (RHS)
This shows that cos²x -sin²x = 2cos²x-1 with the aid of PYTHAGORAS THEOREM
The sum of the angles equals 180
therefore
x+(1/4x)=180
1 1/4 x = 180
x=180/ 1 1/4
x=144
1/4 x =1/4(144)=36
Closing parenthesis is misplaced. Should be:
<span>A = h(b₁ + b₂)/2 </span>
<span>h = 75 ft </span>
<span>b₁ = 125 ft </span>
<span>b₂ = 81 ft </span>
<span>Then it's just plug & grind: </span>
<span>A = 75(125 + 81)/2 ft² = 75·206/2 ft² = 75·103 ft² = (7500 + 225) ft² = 7725 ft² </span>
<span>If you follow that, it will guide you through any other, similar p</span>
Answer:
your answer would be 190 all u do is add
Step-by-step explanation:
