
We know that : (a - b)(a + b) = a² - b²

We know that : 1 - sin²x = cos²x



We know that : sec²x = 1 + tan²x







Question 14, Part (i)
Focus on quadrilateral ABCD. The interior angles add to 360 (this is true for any quadrilateral), so,
A+B+C+D = 360
A+90+C+90 = 360
A+C+180 = 360
A+C = 360-180
A+C = 180
Since angles A and C add to 180, this shows they are supplementary. This is the same as saying angles 2 and 3 are supplementary.
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Question 14, Part (ii)
Let
x = measure of angle 1
y = measure of angle 2
z = measure of angle 3
Back in part (i) above, we showed that y + z = 180
Note that angles 1 and 2 are adjacent to form a straight line, so we can say
x+y = 180
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We have the two equations x+y = 180 and y+z = 180 to form this system of equations

Which is really the same as this system

The 0s help align the y terms up. Subtracting straight down leads to the equation x-z = 0 and we can solve to get x = z. Therefore showing that angle 1 and angle 3 are congruent. We could also use the substitution rule to end up with x = z as well.
Answer:
77 degrees.
Step-by-step explanation:
180-103=77
Answer:
To give more clarity to the question, lets examine the attached back-to-back stem plot.
A)
Having examined the stem plot, we can using quick calculations, summarize that:
The mean (40.45 cal/kg) and median (41 cal/kg) daily caloric intake of ninth-grade students in the rural school is higher than the corresponding measures of center, mean (32.6 cal/kg) and median (32 cal/kg), for ninth-graders in the urban school.
The median and the mean for the students in the 9th grade in the urban school is lower than that of those of their contemporaries in the rural school. The respective medians and means are stated below:
Urban 9th Grade Students
Median = 32 cal/kg
Mean = 36 cal/kg
Rural 9th Grade Students
Median = 41 cal/kg
Mean = 41 cal/kg
Please note that all figures above have been approximated to the nearest whole number.
B)
It is unreasonable to generalize the findings of this study to all rural and urban 9th-grade students in the United States because the sample is too small compared to the target population size.
To allow for generalization, they would have to collect and analyze more samples say from every state within America.
Cheers!