Answer: X = 7√2
Step-by-step explanation:
Let first Consider triangle BDC,
Cos C = adjacent/ hypothenus
Cos C = 7 / x ...... (1)
Also, let consider triangle ABC
Cos C = adjacent / hypothenus
Cos C = x / 14 ....... (2)
Since angle C is the same, equate equation 1 to 2
7/ x = x / 14
Cross multiply
X^2 = 98
Make x the subject of formula
X = sqrt (98)
X = sqrt ( 49 × 2 )
X = sqrt (49) × sqrt (2)
X = 7 sqrt(2)
X = 7√2
Answer:
4y = 2
Step-by-step explanation:
9y + 5 = 7 + 3y + 2y
9y-2y-3y=7-5
4y=2
Answer:
(0 , -a²)
Step-by-step explanation:
tangent at x = a and x = -a
y = x² (a , a²) and (-a , a²) must be on the curve and tangent to curve
gradient dy/dx = 2x
slope (m) at x = a is <u>2a</u> and slope (m') at x=-a is<u> -2a</u>
line1: (y - a²) / (x - a) = 2a
y - a² = 2a (x - a) y = 2ax - a² ... (1)
line2: (y - a²) / (x + a) = - 2a y = -2ax- a² ... (2)
(1) - (2): 4ax = 0 a≠0 x = 0
y = - a²
I wish I did it right, or ....