The slope of the normal to the curve x = t2 + 3t – 8, y = 2t2 – 2t – 5 at the point (–10, –1) is वक्र x = t2 + 3t – 8, y = 2t2 – 2t – 5 के बिंदु (–10, –1) पर अभिलम्ब की प्रवणता है